CIS 1.7 Self-Assessment Guide

Overview

This document is a companion to the RKE2 security hardening guide. The hardening guide provides prescriptive guidance for hardening a production installation of RKE2, and this benchmark guide is meant to help you evaluate the level of security of the hardened cluster against each control in the CIS Kubernetes benchmark. It is to be used by RKE2 operators, security teams, auditors, and decision makers.

This guide is specific to the v1.25 release line of RKE2 and the v1.7 release of the CIS Kubernetes Benchmark.

For more information about each control, including detailed rationales and descriptions checks, you can refer to the corresponding section of the CIS Kubernetes Benchmark v1.7. You can download the benchmark, after creating a free account, in Center for Internet Security (CIS).

Testing controls methodology

Each control in the CIS Kubernetes Benchmark was evaluated against a RKE2 cluster that was configured according to the accompanying hardening guide.

These are the possible results for each control:

• PASS - The RKE2 cluster under test passed the audit outlined in the benchmark.
• Not Applicable - The control is not applicable to RKE2 because of how it is designed to operate. The rationale section will explain why this is so.
• WARN - The control is manual in the CIS benchmark and depends on the manual operator intervention. The remediation section will provide guidance on how to achieve a PASS result.

1 Control Plane Security Configuration

1.1 Control Plane Node Configuration Files

1.1.1 Ensure that the API server pod specification file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

stat -c permissions=%a /var/lib/rancher/rke2/agent/pod-manifests/kube-apiserver.yaml

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/rancher/rke2/agent/pod-manifests/kube-apiserver.yaml

1.1.2 Ensure that the API server pod specification file ownership is set to root:root (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/pod-manifests/kube-apiserver.yaml; then stat -c %U:%G /var/lib/rancher/rke2/agent/pod-manifests/kube-apiserver.yaml; fi'

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /var/lib/rancher/rke2/agent/pod-manifests/kube-apiserver.yaml

1.1.3 Ensure that the controller manager pod specification file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/pod-manifests/kube-controller-manager.yaml; then stat -c permissions=%a /var/lib/rancher/rke2/agent/pod-manifests/kube-controller-manager.yaml; fi'

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/rancher/rke2/agent/pod-manifests/kube-controller-manager.yaml

1.1.4 Ensure that the controller manager pod specification file ownership is set to root:root (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/pod-manifests/kube-controller-manager.yaml; then stat -c %U:%G /var/lib/rancher/rke2/agent/pod-manifests/kube-controller-manager.yaml; fi'

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /var/lib/rancher/rke2/agent/pod-manifests/kube-controller-manager.yaml

1.1.5 Ensure that the scheduler pod specification file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/pod-manifests/kube-scheduler.yaml; then stat -c permissions=%a /var/lib/rancher/rke2/agent/pod-manifests/kube-scheduler.yaml; fi'

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/rancher/rke2/agent/pod-manifests/kube-scheduler.yaml

1.1.6 Ensure that the scheduler pod specification file ownership is set to root:root (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/pod-manifests/kube-scheduler.yaml; then stat -c %U:%G /var/lib/rancher/rke2/agent/pod-manifests/kube-scheduler.yaml; fi'

Expected Result: 'root:root' is present

Returned Value:

root:root

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /var/lib/rancher/rke2/agent/pod-manifests/kube-scheduler.yaml

1.1.7 Ensure that the etcd pod specification file permissions are set to 600 or more restrictive (Manual)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/pod-manifests/etcd.yaml; then stat -c permissions=%a /var/lib/rancher/rke2/agent/pod-manifests/etcd.yaml; fi'

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

If running master only with no etcd role, this check is Not applicable. If controlplane and etcd roles are present on the same nodes but this check is warn then Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/rancher/rke2/agent/pod-manifests/etcd.yaml

1.1.8 Ensure that the etcd pod specification file ownership is set to root:root (Manual)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/pod-manifests/etcd.yaml; then stat -c %U:%G /var/lib/rancher/rke2/agent/pod-manifests/etcd.yaml; fi'

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

Remediation:

If running master only with no etcd role, this check is Not applicable. If controlplane and etcd roles are present on the same nodes but this check is warn then Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /var/lib/rancher/rke2/agent/pod-manifests/etcd.yaml

1.1.9 Ensure that the Container Network Interface file permissions are set to 600 or more restrictive (Manual)

Result: WARN

Remediation: Note that for many CNIs, a lock file is created with permissions 750. This is expected and can be ignored. Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/cni/networks/<filename> and chmod 600 /etc/cni/net.d/<filename>

1.1.10 Ensure that the Container Network Interface file ownership is set to root:root (Manual)

Result: PASS

Audit:

ps -fC ${kubeletbin:-kubelet} | grep -- --cni-conf-dir || echo "/etc/cni/net.d" | sed 's%.*cni-conf-dir[= ]\([^ ]*\).*%\1%' | xargs -I{} find {} -mindepth 1 | xargs --no-run-if-empty stat -c %U:%G
find /var/lib/cni/networks -type f 2> /dev/null | xargs --no-run-if-empty stat -c %U:%G

Expected Result: 'root:root' is present

Returned Value:

root:root
root:root
root:root
root:root
root:root
root:root
root:root
root:root
root:root
root:root

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root <path/to/cni/files>

1.1.11 Ensure that the etcd data directory permissions are set to 700 or more restrictive (Manual)

Result: PASS

Audit:

stat -c permissions=%a /var/lib/rancher/rke2/server/db/etcd

Expected Result: permissions has permissions 700, expected 700 or more restrictive

Returned Value:

permissions=700

Remediation:

If running master only with no etcd role, this check is Not applicable. If controlplane and etcd roles are present on the same nodes but this check is warn then On the etcd server node, get the etcd data directory, passed as an argument --data-dir, from the command 'ps -ef | grep etcd'. Run the below command (based on the etcd data directory found above). For example, chmod 700 /var/lib/rancher/rke2/server/db/etcd

1.1.12 Ensure that the etcd data directory ownership is set to etcd:etcd (Manual)

Result: PASS

Audit:

stat -c %U:%G /var/lib/rancher/rke2/server/db/etcd

Expected Result: 'etcd:etcd' is present

Returned Value:

etcd:etcd

Remediation:

If running master only with no etcd role, this check is Not applicable. If controlplane and etcd roles are present on the same nodes but this check is warn then On the etcd server node, get the etcd data directory, passed as an argument --data-dir, from the command 'ps -ef | grep etcd'. Run the below command (based on the etcd data directory found above). For example, chown etcd:etcd /var/lib/rancher/rke2/server/db/etcd

1.1.13 Ensure that the admin.conf file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

stat -c permissions=%a /var/lib/rancher/rke2/server/cred/admin.kubeconfig

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/rancher/rke2/server/cred/admin.kubeconfig

1.1.14 Ensure that the admin.conf file ownership is set to root:root (Automated)

Result: PASS

Audit:

stat -c %U:%G /var/lib/rancher/rke2/server/cred/admin.kubeconfig

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /var/lib/rancher/rke2/server/cred/admin.kubeconfig

1.1.15 Ensure that the scheduler.conf file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/server/cred/scheduler.kubeconfig; then stat -c permissions=%a /var/lib/rancher/rke2/server/cred/scheduler.kubeconfig; fi'

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/rancher/rke2/server/cred/scheduler.kubeconfig

1.1.16 Ensure that the scheduler.conf file ownership is set to root:root (Automated)

Result: PASS

Audit:

stat -c %U:%G /var/lib/rancher/rke2/server/cred/scheduler.kubeconfig

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /var/lib/rancher/rke2/server/cred/scheduler.kubeconfig

1.1.17 Ensure that the controller-manager.conf file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/server/cred/controller.kubeconfig; then stat -c permissions=%a /var/lib/rancher/rke2/server/cred/controller.kubeconfig; fi'

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/rancher/rke2/server/cred/controller.kubeconfig

1.1.18 Ensure that the controller-manager.conf file ownership is set to root:root (Automated)

Result: PASS

Audit:

stat -c %U:%G /var/lib/rancher/rke2/server/cred/controller.kubeconfig

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /var/lib/rancher/rke2/server/cred/controller.kubeconfig

1.1.19 Ensure that the Kubernetes PKI directory and file ownership is set to root:root (Automated)

Result: PASS

Audit:

stat -c %U:%G /var/lib/rancher/rke2/server/tls

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chown -R root:root /var/lib/rancher/rke2/server/tls

1.1.20 Ensure that the Kubernetes PKI certificate file permissions are set to 600 or more restrictive (Manual)

Result: WARN

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chmod -R 600 /var/lib/rancher/rke2/server/tls/*.crt

1.1.21 Ensure that the Kubernetes PKI key file permissions are set to 600 (Automated)

Result: PASS

Audit:

stat -c permissions=%a /var/lib/rancher/rke2/server/tls/*.key

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600
permissions=600

Remediation:

Run the below command (based on the file location on your system) on the control plane node. For example, chmod -R 600 /var/lib/rancher/rke2/server/tls/*.key

1.2 API Server

1.2.1 Ensure that the --anonymous-auth argument is set to false (Manual)

Result: WARN

Remediation: By default, RKE2 sets the --anonymous-auth argument to false. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove anything similar to below.

kube-apiserver-arg:
  - "anonymous-auth=true"

1.2.2 Ensure that the --token-auth-file parameter is not set (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--token-auth-file' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

Follow the documentation and configure alternate mechanisms for authentication. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove anything similar to below.

kube-apiserver-arg:
  - "token-auth-file=<path>"

1.2.3 Ensure that the --DenyServiceExternalIPs is set (Manual)

Result: WARN

Remediation: By default, RKE2 does not set DenyServiceExternalIPs. To enable this flag, edit the RKE2 config file /etc/rancher/rke2/config.yaml like below.

kube-apiserver-arg:
  - "enable-admission-plugins=DenyServiceExternalIPs"

1.2.4 Ensure that the --kubelet-client-certificate and --kubelet-client-key arguments are set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--kubelet-client-certificate' is present AND '--kubelet-client-key' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 automatically provides the kubelet client certificate and key. They are generated and located at /var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt and /var/lib/rancher/rke2/server/tls/client-kube-apiserver.key If for some reason you need to provide your own certificate and key, you can set the below parameters in the RKE2 config file /etc/rancher/rke2/config.yaml.

kube-apiserver-arg:
  - "kubelet-client-certificate=<path/to/client-cert-file>"
  - "kubelet-client-key=<path/to/client-key-file>"

1.2.5 Ensure that the --kubelet-certificate-authority argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--kubelet-certificate-authority' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 automatically provides the kubelet CA cert file, at /var/lib/rancher/rke2/server/tls/server-ca.crt. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-apiserver-arg:
  - "kubelet-certificate-authority=<path/to/ca-cert-file>"

1.2.6 Ensure that the --authorization-mode argument is not set to AlwaysAllow (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--authorization-mode' does not have 'AlwaysAllow'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 does not set the --authorization-mode to AlwaysAllow. If this check fails, edit RKE2 config file /etc/rancher/rke2/config.yaml, remove any lines like below.

kube-apiserver-arg:
  - "authorization-mode=AlwaysAllow"

1.2.7 Ensure that the --authorization-mode argument includes Node (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--authorization-mode' has 'Node'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 sets the --authorization-mode to Node and RBAC. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml, ensure that you are not overriding authorization-mode.

1.2.8 Ensure that the --authorization-mode argument includes RBAC (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--authorization-mode' has 'RBAC'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 sets the --authorization-mode to Node and RBAC. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml, ensure that you are not overriding authorization-mode.

1.2.9 Ensure that the admission control plugin EventRateLimit is set (Manual)

Result: WARN

Remediation: Follow the Kubernetes documentation and set the desired limits in a configuration file. Then, edit the RKE2 config file /etc/rancher/rke2/config.yaml and set the below parameters.

kube-apiserver-arg:
  - "enable-admission-plugins=...,EventRateLimit,..."
  - "admission-control-config-file=<path/to/configuration/file>"

1.2.10 Ensure that the admission control plugin AlwaysAdmit is not set (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--enable-admission-plugins' does not have 'AlwaysAdmit' OR '--enable-admission-plugins' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 does not set the --enable-admission-plugins to AlwaysAdmit. If this check fails, edit RKE2 config file /etc/rancher/rke2/config.yaml, remove any lines like below.

kube-apiserver-arg:
  - "enable-admission-plugins=AlwaysAdmit"

1.2.11 Ensure that the admission control plugin AlwaysPullImages is set (Manual)

Result: WARN

Remediation: Permissive, per CIS guidelines, "This setting could impact offline or isolated clusters, which have images pre-loaded and do not have access to a registry to pull in-use images. This setting is not appropriate for clusters which use this configuration." Edit the RKE2 config file /etc/rancher/rke2/config.yaml on the control plane node and set the --enable-admission-plugins parameter to include AlwaysPullImages. --enable-admission-plugins=...,AlwaysPullImages,...

1.2.12 Ensure that the admission control plugin SecurityContextDeny is set if PodSecurityPolicy is not used (Manual)

Result: Not Applicable

Rationale:

Enabling Pod Security Policy is no longer supported on RKE2 v1.25+ and will cause applications to unexpectedly fail.

1.2.13 Ensure that the admission control plugin ServiceAccount is set (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--disable-admission-plugins' is present OR '--disable-admission-plugins' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 does not set the --disable-admission-plugins to anything. Follow the documentation and create ServiceAccount objects as per your environment. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-apiserver-arg:
  - "disable-admission-plugins=ServiceAccount"

1.2.14 Ensure that the admission control plugin NamespaceLifecycle is set (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--disable-admission-plugins' is present OR '--disable-admission-plugins' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 does not set the --disable-admission-plugins to anything. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-apiserver-arg:
  - "disable-admission-plugins=...,NamespaceLifecycle,..."

1.2.15 Ensure that the admission control plugin NodeRestriction is set (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--enable-admission-plugins' has 'NodeRestriction'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 sets the --enable-admission-plugins to NodeRestriction. Check the RKE2 config file /etc/rancher/rke2/config.yaml, and ensure that you are not overriding the admission plugins. If you are, include NodeRestriction in the list.

kube-apiserver-arg:
  - "enable-admission-plugins=...,NodeRestriction,..."

1.2.16 Ensure that the --secure-port argument is not set to 0 - NoteThis recommendation is obsolete and will be deleted per the consensus process (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--secure-port' is greater than 0 OR '--secure-port' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

Edit the API server pod specification file /var/lib/rancher/rke2/agent/pod-manifests/kube-apiserver.yaml on the control plane node and either remove the --secure-port parameter or set it to a different (non-zero) desired port.

1.2.17 Ensure that the --profiling argument is set to false (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--profiling' is equal to 'false'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 sets the --profiling argument to false. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-apiserver-arg:
  - "profiling=true"

1.2.18 Ensure that the --audit-log-path argument is set (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--audit-log-path' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 sets the --audit-log-path argument to /var/lib/rancher/rke2/server/logs/audit.log If you want to change this, edit the RKE2 config file /etc/rancher/rke2/config.yaml on the control plane node and set the --audit-log-path parameter to a suitable path and file where you would like audit logs to be written, for example,

kube-apiserver-arg:
  - "audit-log-path=/var/log/rke2/audit.log"

1.2.19 Ensure that the --audit-log-maxage argument is set to 30 or as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--audit-log-maxage' is greater or equal to 30

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 sets the --audit-log-maxage argument to 30 days. If you want to change this, edit the RKE2 config file /etc/rancher/rke2/config.yaml on the control plane node and set the --audit-log-maxage parameter to an appropriate number of days, for example,

kube-apiserver-arg:
  - "audit-log-maxage=40"

1.2.20 Ensure that the --audit-log-maxbackup argument is set to 10 or as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--audit-log-maxbackup' is greater or equal to 10

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 sets the --audit-log-maxbackup argument to 10. If you want to change this, edit the RKE2 config file /etc/rancher/rke2/config.yaml on the control plane node and set the --audit-log-maxbackup parameter to an appropriate value. For example,

kube-apiserver-arg:
  - "audit-log-maxbackup=15"

1.2.21 Ensure that the --audit-log-maxsize argument is set to 100 or as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--audit-log-maxsize' is greater or equal to 100

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 sets the --audit-log-maxsize argument to 100 MB. If you want to change this, edit the RKE2 config file /etc/rancher/rke2/config.yaml on the control plane node and set the --audit-log-maxsize parameter to an appropriate size in MB. For example,

kube-apiserver-arg:
  - "audit-log-maxsize=150"

1.2.22 Ensure that the --request-timeout argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--request-timeout' is not present OR '--request-timeout' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

Permissive, per CIS guidelines, "it is recommended to set this limit as appropriate and change the default limit of 60 seconds only if needed". Edit the RKE2 config file /etc/rancher/rke2/config.yaml and set the below parameter if needed. For example,

kube-apiserver-arg:
  - "request-timeout=300s"

1.2.23 Ensure that the --service-account-lookup argument is set to true (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--service-account-lookup' is not present OR '--service-account-lookup' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 does not set the --service-account-lookup argument. Edit the RKE2 config file /etc/rancher/rke2/config.yaml and set the service-account-lookup. For example,

kube-apiserver-arg:
  - "service-account-lookup=true"

Alternatively, you can delete the service-account-lookup parameter from this file so that the default takes effect.

1.2.24 Ensure that the --service-account-key-file argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--service-account-key-file' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

RKE2 automatically generates and sets the service account key file. It is located at /var/lib/rancher/rke2/server/tls/service.key. If this check fails, edit RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-apiserver-arg:
  - "service-account-key-file=<path>"

1.2.25 Ensure that the --etcd-certfile and --etcd-keyfile arguments are set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--etcd-certfile' is present AND '--etcd-keyfile' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

RKE2 automatically generates and sets the etcd certificate and key files. They are located at /var/lib/rancher/rke2/server/tls/etcd/client.crt and /var/lib/rancher/rke2/server/tls/etcd/client.key. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-apiserver-arg:
  - "etcd-certfile=<path>"
  - "etcd-keyfile=<path>"

1.2.26 Ensure that the --tls-cert-file and --tls-private-key-file arguments are set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--tls-cert-file' is present AND '--tls-private-key-file' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 automatically generates and provides the TLS certificate and private key for the apiserver. They are generated and located at /var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt and /var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-apiserver-arg:
  - "tls-cert-file=<path>"
  - "tls-private-key-file=<path>"

1.2.27 Ensure that the --client-ca-file argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--client-ca-file' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 automatically provides the client certificate authority file. It is generated and located at /var/lib/rancher/rke2/server/tls/client-ca.crt. If for some reason you need to provide your own ca certificate, look at using the rke2 certificate command line tool. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-apiserver-arg:
  - "client-ca-file=<path>"

1.2.28 Ensure that the --etcd-cafile argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--etcd-cafile' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, RKE2 automatically provides the etcd certificate authority file. It is generated and located at /var/lib/rancher/rke2/server/tls/client-ca.crt. If for some reason you need to provide your own ca certificate, look at using the rke2 certificate command line tool. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-apiserver-arg:
  - "etcd-cafile=<path>"

1.2.29 Ensure that the --encryption-provider-config argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--encryption-provider-config' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

RKE2 always is configured to encrypt secrets. Secrets encryption is managed with the rke2 secrets-encrypt command line tool. If needed, you can find the generated encryption config at /var/lib/rancher/rke2/server/cred/encryption-config.json

1.2.30 Ensure that encryption providers are appropriately configured (Automated)

Result: PASS

Audit:

ENCRYPTION_PROVIDER_CONFIG=$(ps -ef | grep kube-apiserver | grep -- --encryption-provider-config | sed 's%.*encryption-provider-config[= ]\([^ ]*\).*%\1%')
if test -e $ENCRYPTION_PROVIDER_CONFIG; then grep -o 'providers\"\:\[.*\]' $ENCRYPTION_PROVIDER_CONFIG | grep -o "[A-Za-z]*" | head -2 | tail -1  | sed 's/^/provider=/'; fi

Expected Result: 'provider' contains valid elements from 'aescbc,kms,secretbox'

Returned Value:

provider=aescbc

Remediation:

RKE2 always is configured to use the aescbc encryption provider to encrypt secrets. Secrets encryption is managed with the rke2 secrets-encrypt command line tool. If needed, you can find the generated encryption config at /var/lib/rancher/rke2/server/cred/encryption-config.json

1.2.31 Ensure that the API Server only makes use of Strong Cryptographic Ciphers (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-apiserver

Expected Result: '--tls-cipher-suites' contains valid elements from 'TLS_AES_128_GCM_SHA256,TLS_AES_256_GCM_SHA384,TLS_CHACHA20_POLY1305_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,TLS_RSA_WITH_3DES_EDE_CBC_SHA,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_256_GCM_SHA384'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key

Remediation:

By default, the RKE2 kube-apiserver complies with this test. Changes to these values may cause regression, therefore ensure that all apiserver clients support the new TLS configuration before applying it in production deployments. If a custom TLS configuration is required, consider also creating a custom version of this rule that aligns with your requirements. If this check fails, remove any custom configuration around tls-cipher-suites or update the /etc/rancher/rke2/config.yaml file to match the default by adding the following: kube-apiserver-arg:

• "tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305"

1.3 Controller Manager

1.3.1 Ensure that the --terminated-pod-gc-threshold argument is set as appropriate (Manual)

Result: PASS

Audit:

/bin/ps -fC kube-controller-manager

Expected Result: '--terminated-pod-gc-threshold' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2655    2552  1 18:52 ?        00:00:04 kube-controller-manager --flex-volume-plugin-dir=/var/lib/kubelet/volumeplugins --terminated-pod-gc-threshold=1000 --permit-port-sharing=true --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/rke2/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --use-service-account-credentials=true

Remediation:

By default, RKE2 sets a terminated-pod-gc-threshold of 1000. If you need to change this value, edit the RKE2 config file /etc/rancher/rke2/config.yaml on the control plane node and set the --terminated-pod-gc-threshold to an appropriate threshold,

kube-controller-manager-arg:
  - "terminated-pod-gc-threshold=10"

1.3.2 Ensure that the --profiling argument is set to false (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-controller-manager

Expected Result: '--profiling' is equal to 'false'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2655    2552  1 18:52 ?        00:00:04 kube-controller-manager --flex-volume-plugin-dir=/var/lib/kubelet/volumeplugins --terminated-pod-gc-threshold=1000 --permit-port-sharing=true --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/rke2/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --use-service-account-credentials=true

Remediation:

By default, RKE2 sets the --profiling argument to false. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-controller-manager-arg:
  - "profiling=true"

1.3.3 Ensure that the --use-service-account-credentials argument is set to true (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-controller-manager

Expected Result: '--use-service-account-credentials' is not equal to 'false'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2655    2552  1 18:52 ?        00:00:04 kube-controller-manager --flex-volume-plugin-dir=/var/lib/kubelet/volumeplugins --terminated-pod-gc-threshold=1000 --permit-port-sharing=true --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/rke2/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --use-service-account-credentials=true

Remediation:

By default, RKE2 sets the --use-service-account-credentials argument to true. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-controller-manager-arg:
  - "use-service-account-credentials=false"

1.3.4 Ensure that the --service-account-private-key-file argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-controller-manager

Expected Result: '--service-account-private-key-file' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2655    2552  1 18:52 ?        00:00:04 kube-controller-manager --flex-volume-plugin-dir=/var/lib/kubelet/volumeplugins --terminated-pod-gc-threshold=1000 --permit-port-sharing=true --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/rke2/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --use-service-account-credentials=true

Remediation:

By default, RKE2 automatically provides the service account private key file. It is generated and located at /var/lib/rancher/rke2/server/tls/service.current.key. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-controller-manager-arg:
  - "service-account-private-key-file=<path>"

1.3.5 Ensure that the --root-ca-file argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-controller-manager

Expected Result: '--root-ca-file' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2655    2552  1 18:52 ?        00:00:04 kube-controller-manager --flex-volume-plugin-dir=/var/lib/kubelet/volumeplugins --terminated-pod-gc-threshold=1000 --permit-port-sharing=true --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/rke2/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --use-service-account-credentials=true

Remediation:

By default, RKE2 automatically provides the root CA file. It is generated and located at /var/lib/rancher/rke2/server/tls/server-ca.crt. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-controller-manager-arg:
  - "root-ca-file=<path>"

1.3.6 Ensure that the RotateKubeletServerCertificate argument is set to true (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-controller-manager

Expected Result: '--feature-gates' does not have 'RotateKubeletServerCertificate=false' OR '--feature-gates' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2655    2552  1 18:52 ?        00:00:04 kube-controller-manager --flex-volume-plugin-dir=/var/lib/kubelet/volumeplugins --terminated-pod-gc-threshold=1000 --permit-port-sharing=true --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/rke2/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --use-service-account-credentials=true

Remediation:

Edit the Controller Manager pod specification file /var/lib/rancher/rke2/agent/pod-manifests/kube-controller-manager.yaml on the control plane node and set the --feature-gates parameter to include RotateKubeletServerCertificate=true. --feature-gates=RotateKubeletServerCertificate=true

1.3.7 Ensure that the --bind-address argument is set to 127.0.0.1 (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-controller-manager

Expected Result: '--bind-address' is equal to '127.0.0.1' OR '--bind-address' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2655    2552  1 18:52 ?        00:00:04 kube-controller-manager --flex-volume-plugin-dir=/var/lib/kubelet/volumeplugins --terminated-pod-gc-threshold=1000 --permit-port-sharing=true --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/rke2/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --use-service-account-credentials=true

Remediation:

By default, RKE2 sets the --bind-address argument to 127.0.0.1 If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-controller-manager-arg:
  - "bind-address=<IP>"

1.4 Scheduler

1.4.1 Ensure that the --profiling argument is set to false (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-scheduler

Expected Result: '--profiling' is equal to 'false'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2666    2555  0 18:52 ?        00:00:01 kube-scheduler --permit-port-sharing=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/scheduler.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/scheduler.kubeconfig --bind-address=127.0.0.1 --kubeconfig=/var/lib/rancher/rke2/server/cred/scheduler.kubeconfig --profiling=false --secure-port=10259

Remediation:

By default, RKE2 sets the --profiling argument to false. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-scheduler-arg:
  - "profiling=true"

1.4.2 Ensure that the --bind-address argument is set to 127.0.0.1 (Automated)

Result: PASS

Audit:

/bin/ps -fC kube-scheduler

Expected Result: '--bind-address' is equal to '127.0.0.1' OR '--bind-address' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2666    2555  0 18:52 ?        00:00:01 kube-scheduler --permit-port-sharing=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/scheduler.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/scheduler.kubeconfig --bind-address=127.0.0.1 --kubeconfig=/var/lib/rancher/rke2/server/cred/scheduler.kubeconfig --profiling=false --secure-port=10259

Remediation:

By default, RKE2 sets the --bind-address argument to 127.0.0.1 If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines like below.

kube-scheduler-arg:
  - "bind-address=<IP>"

2 Etcd Node Configuration

2.1 Ensure that the --cert-file and --key-file arguments are set as appropriate (Automated)

Result: PASS

Audit:

Expected Result: '.client-transport-security.cert-file' is equal to '/var/lib/rancher/rke2/server/tls/etcd/server-client.crt' AND '.client-transport-security.key-file' is equal to '/var/lib/rancher/rke2/server/tls/etcd/server-client.key'

Returned Value:

advertise-client-urls: https://10.10.10.100:2379
client-transport-security:
  cert-file: /var/lib/rancher/rke2/server/tls/etcd/server-client.crt
  client-cert-auth: true
  key-file: /var/lib/rancher/rke2/server/tls/etcd/server-client.key
  trusted-ca-file: /var/lib/rancher/rke2/server/tls/etcd/server-ca.crt
data-dir: /var/lib/rancher/rke2/server/db/etcd
election-timeout: 5000
experimental-initial-corrupt-check: true
heartbeat-interval: 500
initial-advertise-peer-urls: https://10.10.10.100:2380
initial-cluster: server-0-43eb3aad=https://10.10.10.100:2380
initial-cluster-state: new
listen-client-http-urls: https://127.0.0.1:2382
listen-client-urls: https://127.0.0.1:2379,https://10.10.10.100:2379
listen-metrics-urls: http://127.0.0.1:2381
listen-peer-urls: https://127.0.0.1:2380,https://10.10.10.100:2380
log-outputs:
- stderr
logger: zap
name: server-0-43eb3aad
peer-transport-security:
  cert-file: /var/lib/rancher/rke2/server/tls/etcd/peer-server-client.crt
  client-cert-auth: true
  key-file: /var/lib/rancher/rke2/server/tls/etcd/peer-server-client.key
  trusted-ca-file: /var/lib/rancher/rke2/server/tls/etcd/peer-ca.crt
snapshot-count: 10000

Remediation:

By default, RKE2 generates cert and key files for etcd. These are located in /var/lib/rancher/rke2/server/tls/etcd/. If this check fails, ensure that the configuration file /var/lib/rancher/rke2/server/db/etcd/config has not been modified to use custom cert and key files.

2.2 Ensure that the --client-cert-auth argument is set to true (Automated)

Result: PASS

Audit:

/bin/ps -fC etcd

Expected Result: 'ETCD_CLIENT_CERT_AUTH' is present OR '.client-transport-security.client-cert-auth' is equal to 'true'

Returned Value:

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=server-0
ETCD_UNSUPPORTED_ARCH=
FILE_HASH=89670f57382642704d89307891be3ba62144d3f1018d38ea0db9e4bb32c9a61c
NO_PROXY=.svc,.cluster.local,10.42.0.0/16,10.43.0.0/16
HOME=/

Remediation:

By default, RKE2 sets the --client-cert-auth parameter to true. If this check fails, ensure that the configuration file /var/lib/rancher/rke2/server/db/etcd/config has not been modified to disable client certificate authentication.

2.3 Ensure that the --auto-tls argument is not set to true (Automated)

Result: PASS

Audit:

/bin/ps -fC etcd

Expected Result: 'ETCD_AUTO_TLS' is not present OR 'ETCD_AUTO_TLS' is present OR '.client-transport-security.auto-tls' is present

Returned Value:

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=server-0
ETCD_UNSUPPORTED_ARCH=
FILE_HASH=89670f57382642704d89307891be3ba62144d3f1018d38ea0db9e4bb32c9a61c
NO_PROXY=.svc,.cluster.local,10.42.0.0/16,10.43.0.0/16
HOME=/

Remediation:

By default, RKE2 does not set the --auto-tls parameter. If this check fails, edit the etcd pod specification file /var/lib/rancher/rke2/server/db/etcd/config on the master node and either remove the --auto-tls parameter or set it to false. client-transport-security: auto-tls: false

2.4 Ensure that the --peer-cert-file and --peer-key-file arguments are set as appropriate (Automated)

Result: PASS

Audit:

Expected Result: '.peer-transport-security.cert-file' is equal to '/var/lib/rancher/rke2/server/tls/etcd/peer-server-client.crt' AND '.peer-transport-security.key-file' is equal to '/var/lib/rancher/rke2/server/tls/etcd/peer-server-client.key'

Returned Value:

advertise-client-urls: https://10.10.10.100:2379
client-transport-security:
  cert-file: /var/lib/rancher/rke2/server/tls/etcd/server-client.crt
  client-cert-auth: true
  key-file: /var/lib/rancher/rke2/server/tls/etcd/server-client.key
  trusted-ca-file: /var/lib/rancher/rke2/server/tls/etcd/server-ca.crt
data-dir: /var/lib/rancher/rke2/server/db/etcd
election-timeout: 5000
experimental-initial-corrupt-check: true
heartbeat-interval: 500
initial-advertise-peer-urls: https://10.10.10.100:2380
initial-cluster: server-0-43eb3aad=https://10.10.10.100:2380
initial-cluster-state: new
listen-client-http-urls: https://127.0.0.1:2382
listen-client-urls: https://127.0.0.1:2379,https://10.10.10.100:2379
listen-metrics-urls: http://127.0.0.1:2381
listen-peer-urls: https://127.0.0.1:2380,https://10.10.10.100:2380
log-outputs:
- stderr
logger: zap
name: server-0-43eb3aad
peer-transport-security:
  cert-file: /var/lib/rancher/rke2/server/tls/etcd/peer-server-client.crt
  client-cert-auth: true
  key-file: /var/lib/rancher/rke2/server/tls/etcd/peer-server-client.key
  trusted-ca-file: /var/lib/rancher/rke2/server/tls/etcd/peer-ca.crt
snapshot-count: 10000

Remediation:

By default, RKE2 generates peer cert and key files for etcd. These are located in /var/lib/rancher/rke2/server/tls/etcd/. If this check fails, ensure that the configuration file /var/lib/rancher/rke2/server/db/etcd/config has not been modified to use custom peer cert and key files.

2.5 Ensure that the --peer-client-cert-auth argument is set to true (Automated)

Result: PASS

Audit:

/bin/ps -fC etcd

Expected Result: 'ETCD_PEER_CLIENT_CERT_AUTH' is present OR '.peer-transport-security.client-cert-auth' is equal to 'true'

Returned Value:

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=server-0
ETCD_UNSUPPORTED_ARCH=
FILE_HASH=89670f57382642704d89307891be3ba62144d3f1018d38ea0db9e4bb32c9a61c
NO_PROXY=.svc,.cluster.local,10.42.0.0/16,10.43.0.0/16
HOME=/

Remediation:

By default, RKE2 sets the --peer-cert-auth parameter to true. If this check fails, ensure that the configuration file /var/lib/rancher/rke2/server/db/etcd/config has not been modified to disable peer client certificate authentication.

2.6 Ensure that the --peer-auto-tls argument is not set to true (Automated)

Result: PASS

Audit:

/bin/ps -fC etcd

Expected Result: 'ETCD_PEER_AUTO_TLS' is not present OR 'ETCD_PEER_AUTO_TLS' is present OR '.peer-transport-security.auto-tls' is present

Returned Value:

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=server-0
ETCD_UNSUPPORTED_ARCH=
FILE_HASH=89670f57382642704d89307891be3ba62144d3f1018d38ea0db9e4bb32c9a61c
NO_PROXY=.svc,.cluster.local,10.42.0.0/16,10.43.0.0/16
HOME=/

Remediation:

By default, RKE2 does not set the --peer-auto-tls parameter. If this check fails, edit the etcd pod specification file /var/lib/rancher/rke2/server/db/etcd/config on the master node and either remove the --peer-auto-tls parameter or set it to false. peer-transport-security: auto-tls: false

2.7 Ensure that a unique Certificate Authority is used for etcd (Automated)

Result: PASS

Audit:

/bin/ps -fC etcd

Expected Result: 'ETCD_TRUSTED_CA_FILE' is present OR '.peer-transport-security.trusted-ca-file' is equal to '/var/lib/rancher/rke2/server/tls/etcd/peer-ca.crt'

Returned Value:

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=server-0
ETCD_UNSUPPORTED_ARCH=
FILE_HASH=89670f57382642704d89307891be3ba62144d3f1018d38ea0db9e4bb32c9a61c
NO_PROXY=.svc,.cluster.local,10.42.0.0/16,10.43.0.0/16
HOME=/

Remediation:

By default, RKE2 generates a unique certificate authority for etcd. This is located at /var/lib/rancher/rke2/server/tls/etcd/peer-ca.crt. If this check fails, ensure that the configuration file /var/lib/rancher/rke2/server/db/etcd/config has not been modified to use a shared certificate authority.

3 Control Plane Configuration

3.1 Authentication and Authorization

3.1.1 Client certificate authentication should not be used for users (Manual)

Result: WARN

Remediation: Alternative mechanisms provided by Kubernetes such as the use of OIDC should be implemented in place of client certificates.

3.1.2 Service account token authentication should not be used for users (Manual)

Result: WARN

Remediation: Alternative mechanisms provided by Kubernetes such as the use of OIDC should be implemented in place of service account tokens.

3.1.3 Bootstrap token authentication should not be used for users (Manual)

Result: WARN

Remediation: Alternative mechanisms provided by Kubernetes such as the use of OIDC should be implemented in place of bootstrap tokens.

3.2 Logging

3.2.1 Ensure that a minimal audit policy is created (Automated)

Result: PASS

Audit:

/bin/ps -ef | grep kube-apiserver | grep -v grep

Expected Result: '--audit-policy-file' is present

Returned Value:

root        2511    2457  9 18:52 ?        00:00:23 kube-apiserver --admission-control-config-file=/etc/rancher/rke2/rke2-pss.yaml --audit-policy-file=/etc/rancher/rke2/audit-policy.yaml --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/rke2/server/logs/audit.log --advertise-address=10.10.10.100 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,rke2 --authorization-mode=Node,RBAC --bind-address=0.0.0.0 --cert-dir=/var/lib/rancher/rke2/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/rke2/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/rke2/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/rke2/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/rke2/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/rke2/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/rke2/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/rke2/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/rke2/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/rke2/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/rke2/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6443 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/rke2/server/tls/service.key --service-account-signing-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/rke2/server/tls/serving-kube-apiserver.key
root        2655    2552  1 18:52 ?        00:00:04 kube-controller-manager --flex-volume-plugin-dir=/var/lib/kubelet/volumeplugins --terminated-pod-gc-threshold=1000 --permit-port-sharing=true --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/rke2/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/rke2/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/rke2/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/rke2/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/rke2/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/rke2/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/rke2/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --use-service-account-credentials=true

Remediation:

Create an audit policy file for your cluster.

3.2.2 Ensure that the audit policy covers key security concerns (Manual)

Result: WARN

Remediation: Review the audit policy provided for the cluster and ensure that it covers at least the following areas,

• Access to Secrets managed by the cluster. Care should be taken to only log Metadata for requests to Secrets, ConfigMaps, and TokenReviews, in order to avoid risk of logging sensitive data.
• Modification of Pod and Deployment objects.
• Use of pods/exec, pods/portforward, pods/proxy and services/proxy. For most requests, minimally logging at the Metadata level is recommended (the most basic level of logging).

4 Worker Node Security Configuration

4.1 Worker Node Configuration Files

4.1.1 Ensure that the kubelet service file permissions are set to 600 or more restrictive (Automated)

Result: Not Applicable

Rationale:

The kubelet is managed by the RKE2 process. There is no kubelet service file, all configuration is passed in as arguments at runtime.

4.1.2 Ensure that the kubelet service file ownership is set to root:root (Automated)

Result: Not Applicable

Rationale:

The kubelet is managed by the RKE2 process. There is no kubelet service file, all configuration is passed in as arguments at runtime.

4.1.3 If proxy kubeconfig file exists ensure permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/kubeproxy.kubeconfig; then stat -c permissions=%a /var/lib/rancher/rke2/agent/kubeproxy.kubeconfig; fi' 

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

Run the below command (based on the file location on your system) on the each worker node. For example, chmod 600 /var/lib/rancher/rke2/agent/kubeproxy.kubeconfig

4.1.4 If proxy kubeconfig file exists ensure ownership is set to root:root (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/kubeproxy.kubeconfig; then stat -c %U:%G /var/lib/rancher/rke2/agent/kubeproxy.kubeconfig; fi' 

Expected Result: 'root:root' is present

Returned Value:

root:root

Remediation:

Run the below command (based on the file location on your system) on the each worker node. For example, chown root:root /var/lib/rancher/rke2/agent/kubeproxy.kubeconfig

4.1.5 Ensure that the --kubeconfig kubelet.conf file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/kubelet.kubeconfig; then stat -c permissions=%a /var/lib/rancher/rke2/agent/kubelet.kubeconfig; fi' 

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

Run the below command (based on the file location on your system) on the each worker node. For example, chmod 600 /var/lib/rancher/rke2/agent/kubelet.kubeconfig

4.1.6 Ensure that the --kubeconfig kubelet.conf file ownership is set to root:root (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/kubelet.kubeconfig; then stat -c %U:%G /var/lib/rancher/rke2/agent/kubelet.kubeconfig; fi' 

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

Remediation:

Run the below command (based on the file location on your system) on the each worker node. For example, chown root:root /var/lib/rancher/rke2/agent/kubelet.kubeconfig

4.1.7 Ensure that the certificate authorities file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/client-ca.crt; then stat -c permissions=%a /var/lib/rancher/rke2/agent/client-ca.crt; fi' 

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

Remediation:

Run the below command (based on the file location on your system) on the each worker node. For example, chmod 600 /var/lib/rancher/rke2/agent/client-ca.crt

4.1.8 Ensure that the client certificate authorities file ownership is set to root:root (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/rke2/agent/client-ca.crt; then stat -c %U:%G /var/lib/rancher/rke2/agent/client-ca.crt; fi' 

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

Remediation:

Run the following command to modify the ownership of the --client-ca-file. chown root:root /var/lib/rancher/rke2/agent/client-ca.crt

4.1.9 If the kubelet config.yaml configuration file is being used validate permissions set to 600 or more restrictive (Automated)

Result: Not Applicable

Rationale:

The kubelet is managed by the RKE2 process. There is no kubelet config file, all configuration is passed in as arguments at runtime.

4.1.10 If the kubelet config.yaml configuration file is being used validate file ownership is set to root:root (Automated)

Result: Not Applicable

Rationale:

The kubelet is managed by the RKE2 process. There is no kubelet config file, all configuration is passed in as arguments at runtime.

4.2 Kubelet

4.2.1 Ensure that the --anonymous-auth argument is set to false (Automated)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: '--anonymous-auth' is equal to 'false'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

By default, RKE2 sets the --anonymous-auth to false. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml, remove any lines similar to below.

kubelet-arg:
  - "anonymous-auth=true"

Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

4.2.2 Ensure that the --authorization-mode argument is not set to AlwaysAllow (Automated)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: '--authorization-mode' does not have 'AlwaysAllow'

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

By default, RKE2 does not set the --authorization-mode to AlwaysAllow. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml, remove any lines similar to below.

kubelet-arg:
  - "authorization-mode=AlwaysAllow"

Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

4.2.3 Ensure that the --client-ca-file argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: '--client-ca-file' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

By default, RKE2 automatically provides the client ca certificate for the Kubelet. It is generated and located at /var/lib/rancher/rke2/agent/client-ca.crt

4.2.4 Verify that the --read-only-port argument is set to 0 (Automated)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: '--read-only-port' is equal to '0' OR '--read-only-port' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

By default, RKE2 sets the --read-only-port to 0. If you have set this to a different value, you should set it back to 0. Edit the RKE2 config file /etc/rancher/rke2/config.yaml, remove any lines similar to below.

kubelet-arg:
  - "read-only-port=XXXX"

Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

4.2.5 Ensure that the --streaming-connection-idle-timeout argument is not set to 0 (Manual)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: '--streaming-connection-idle-timeout' is present OR '--streaming-connection-idle-timeout' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

Edit the RKE2 config file /etc/rancher/rke2/config.yaml, set the following parameter to an appropriate value.

kubelet-arg:
  - "streaming-connection-idle-timeout=5m"

Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

4.2.6 Ensure that the --make-iptables-util-chains argument is set to true (Automated)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: '--make-iptables-util-chains' is present OR '--make-iptables-util-chains' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

Edit the RKE2 config file /etc/rancher/rke2/config.yaml, set the following parameter.

kubelet-arg:
  - "make-iptables-util-chains=true"

Or, remove the --make-iptables-util-chains argument to let RKE2 use the default value. Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

4.2.7 Ensure that the --hostname-override argument is not set (Automated)

Result: Not Applicable

Rationale:

By default, RKE2 does set the --hostname-override argument. Per CIS guidelines, this is to comply with cloud providers that require this flag to ensure that hostname matches node names.

4.2.8 Ensure that the eventRecordQPS argument is set to a level which ensures appropriate event capture (Manual)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: '--event-qps' is present OR '--event-qps' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

Edit the RKE2 config file /etc/rancher/rke2/config.yaml, set the following parameter to an appropriate value.

kubelet-arg:
  - "event-qps=<value>"

Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

4.2.9 Ensure that the --tls-cert-file and --tls-private-key-file arguments are set as appropriate (Automated)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: '--tls-cert-file' is present AND '--tls-private-key-file' is present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

By default, RKE2 automatically provides the TLS certificate and private key for the Kubelet. They are generated and located at /var/lib/rancher/rke2/agent/serving-kubelet.crt and /var/lib/rancher/rke2/agent/serving-kubelet.key If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml and remove any lines similar to below.

kubelet-arg:
  - "tls-cert-file=<path/to/tls-cert-file>"
  - "tls-private-key-file=<path/to/tls-private-key-file>"

4.2.10 Ensure that the --rotate-certificates argument is not set to false (Automated)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: '--rotate-certificates' is present OR '--rotate-certificates' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

By default, RKE2 does not set the --rotate-certificates argument. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml, remove any rotate-certificates parameter. Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

4.2.11 Verify that the RotateKubeletServerCertificate argument is set to true (Automated)

Result: PASS

Audit:

/bin/ps -fC kubelet

Expected Result: 'RotateKubeletServerCertificate' is present OR 'RotateKubeletServerCertificate' is not present

Returned Value:

UID          PID    PPID  C STIME TTY          TIME CMD
root        2292    2256  2 18:52 ?        00:00:07 kubelet --volume-plugin-dir=/var/lib/kubelet/volumeplugins --file-check-frequency=5s --sync-frequency=30s --address=0.0.0.0 --alsologtostderr=false --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/rke2/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/rke2/agent/kubelet.kubeconfig --log-file=/var/lib/rancher/rke2/agent/logs/kubelet.log --log-file-max-size=50 --logtostderr=false --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=index.docker.io/rancher/pause:3.6 --pod-manifest-path=/var/lib/rancher/rke2/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --stderrthreshold=FATAL --tls-cert-file=/var/lib/rancher/rke2/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/rke2/agent/serving-kubelet.key

Remediation:

By default, RKE2 does not set the RotateKubeletServerCertificate feature gate. If this check fails, edit the RKE2 config file /etc/rancher/rke2/config.yaml, remove any RotateKubeletServerCertificate parameter. Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

4.2.12 Ensure that the Kubelet only makes use of Strong Cryptographic Ciphers (Manual)

Result: WARN

Remediation: Edit the RKE2 config file /etc/rancher/rke2/config.yaml,

kubelet-arg:
  - "tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305"

or to a subset of these values. Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

4.2.13 Ensure that a limit is set on pod PIDs (Manual)

Result: WARN

Remediation: Edit the RKE2 config file /etc/rancher/rke2/config.yaml, set the following parameter to an appropriate value.

kubelet-arg:
  - "pod-max-pids=<value>"

Based on your system, restart the RKE2 service. For example, systemctl restart rke2-server.service

5 Kubernetes Policies

5.1 RBAC and Service Accounts

5.1.1 Ensure that the cluster-admin role is only used where required (Manual)

Result: WARN

Remediation: Identify all clusterrolebindings to the cluster-admin role. Check if they are used and if they need this role or if they could use a role with fewer privileges. Where possible, first bind users to a lower privileged role and then remove the clusterrolebinding to the cluster-admin role : kubectl delete clusterrolebinding [name]

5.1.2 Minimize access to secrets (Manual)

Result: WARN

Remediation: Where possible, remove get, list and watch access to Secret objects in the cluster.

5.1.3 Minimize wildcard use in Roles and ClusterRoles (Manual)

Result: WARN

Remediation: Where possible replace any use of wildcards in clusterroles and roles with specific objects or actions.

5.1.4 Minimize access to create pods (Manual)

Result: WARN

Remediation: Where possible, remove create access to pod objects in the cluster.

5.1.5 Ensure that default service accounts are not actively used. (Manual)

Result: WARN

Remediation: Create explicit service accounts wherever a Kubernetes workload requires specific access to the Kubernetes API server. Modify the configuration of each default service account to include this value automountServiceAccountToken: false

5.1.6 Ensure that Service Account Tokens are only mounted where necessary (Manual)

Result: WARN

Remediation: Modify the definition of pods and service accounts which do not need to mount service account tokens to disable it.

5.1.7 Avoid use of system:masters group (Manual)

Result: WARN

Remediation: Remove the system:masters group from all users in the cluster.

5.1.8 Limit use of the Bind, Impersonate and Escalate permissions in the Kubernetes cluster (Manual)

Result: WARN

Remediation: Where possible, remove the impersonate, bind and escalate rights from subjects.

5.1.9 Minimize access to create persistent volumes (Manual)

Result: WARN

Remediation: Where possible, remove create access to PersistentVolume objects in the cluster.

5.1.10 Minimize access to the proxy sub-resource of nodes (Manual)

Result: WARN

Remediation: Where possible, remove access to the proxy sub-resource of node objects.

5.1.11 Minimize access to the approval sub-resource of certificatesigningrequests objects (Manual)

Result: WARN

Remediation: Where possible, remove access to the approval sub-resource of certificatesigningrequest objects.

5.1.12 Minimize access to webhook configuration objects (Manual)

Result: WARN

Remediation: Where possible, remove access to the validatingwebhookconfigurations or mutatingwebhookconfigurations objects

5.1.13 Minimize access to the service account token creation (Manual)

Result: WARN

Remediation: Where possible, remove access to the token sub-resource of serviceaccount objects.

5.2 Pod Security Standards

5.2.1 Ensure that the cluster has at least one active policy control mechanism in place (Manual)

Result: WARN

Remediation: Ensure that either Pod Security Admission or an external policy control system is in place for every namespace which contains user workloads.

5.2.2 Minimize the admission of privileged containers (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of privileged containers.

5.2.3 Minimize the admission of containers wishing to share the host process ID namespace (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of hostPID containers.

5.2.4 Minimize the admission of containers wishing to share the host IPC namespace (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of hostIPC containers.

5.2.5 Minimize the admission of containers wishing to share the host network namespace (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of hostNetwork containers.

5.2.6 Minimize the admission of containers with allowPrivilegeEscalation (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers with .spec.allowPrivilegeEscalation set to true.

5.2.7 Minimize the admission of root containers (Manual)

Result: WARN

Remediation: Create a policy for each namespace in the cluster, ensuring that either MustRunAsNonRoot or MustRunAs with the range of UIDs not including 0, is set.

5.2.8 Minimize the admission of containers with the NET_RAW capability (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers with the NET_RAW capability.

5.2.9 Minimize the admission of containers with added capabilities (Automated)

Result: WARN

Remediation: Ensure that allowedCapabilities is not present in policies for the cluster unless it is set to an empty array.

5.2.10 Minimize the admission of containers with capabilities assigned (Manual)

Result: WARN

Remediation: Review the use of capabilities in applications running on your cluster. Where a namespace contains applications which do not require any Linux capabities to operate consider adding a PSP which forbids the admission of containers which do not drop all capabilities.

5.2.11 Minimize the admission of Windows HostProcess containers (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers that have .securityContext.windowsOptions.hostProcess set to true.

5.2.12 Minimize the admission of HostPath volumes (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers with hostPath volumes.

5.2.13 Minimize the admission of containers which use HostPorts (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers which use hostPort sections.

5.3 Network Policies and CNI

5.3.1 Ensure that the CNI in use supports NetworkPolicies (Manual)

Result: WARN

Remediation: If the CNI plugin in use does not support network policies, consideration should be given to making use of a different plugin, or finding an alternate mechanism for restricting traffic in the Kubernetes cluster.

5.3.2 Ensure that all Namespaces have NetworkPolicies defined (Manual)

Result: WARN

Remediation: Follow the documentation and create NetworkPolicy objects as you need them.

5.4 Secrets Management

5.4.1 Prefer using Secrets as files over Secrets as environment variables (Manual)

Result: WARN

Remediation: If possible, rewrite application code to read Secrets from mounted secret files, rather than from environment variables.

5.4.2 Consider external secret storage (Manual)

Result: WARN

Remediation: Refer to the Secrets management options offered by your cloud provider or a third-party secrets management solution.

5.5 Extensible Admission Control

5.5.1 Configure Image Provenance using ImagePolicyWebhook admission controller (Manual)

Result: WARN

Remediation: Follow the Kubernetes documentation and setup image provenance.

5.7 General Policies

5.7.1 Create administrative boundaries between resources using namespaces (Manual)

Result: WARN

Remediation: Follow the documentation and create namespaces for objects in your deployment as you need them.

5.7.2 Ensure that the seccomp profile is set to docker/default in your Pod definitions (Manual)

Result: WARN

Remediation: Use securityContext to enable the docker/default seccomp profile in your pod definitions. An example is as below: securityContext: seccompProfile: type: RuntimeDefault

5.7.3 Apply SecurityContext to your Pods and Containers (Manual)

Result: WARN

Remediation: Follow the Kubernetes documentation and apply SecurityContexts to your Pods. For a suggested list of SecurityContexts, you may refer to the CIS Security Benchmark for Docker Containers.

5.7.4 The default namespace should not be used (Manual)

Result: WARN

Remediation: Ensure that namespaces are created to allow for appropriate segregation of Kubernetes resources and that all new resources are created in a specific namespace.