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Version 1.22 CIS Kubernetes benchmark

Version 1.22 CIS Kubernetes benchmark

This version is no longer supported. Update your cluster to a supported version as soon as possible.

The Center for Internet Security (CIS) publishes the CIS Kubernetes Benchmark as a framework of specific steps to configure Kubernetes more securely and with standards that are commensurate to various industry regulations. This document contains the results of the version 1.5 CIS Kubernetes benchmark for clusters that run Kubernetes version 1.22. For more information or help understanding the benchmark, see Using the benchmark.

1 Master node security configuration

Review the Master node security configuration results of the version 1.5 CIS Kubernetes benchmark.

1.1 Master node configuration files

Section 1.1 Master node benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
1.1.1 Ensure that the API server pod specification file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
1.1.2 Ensure that the API server pod specification file ownership is set to root:root. Scored 1 Pass IBM
1.1.3 Ensure that the controller manager pod specification file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
1.1.4 Ensure that the controller manager pod specification file ownership is set to root:root. Scored 1 Pass IBM
1.1.5 Ensure that the scheduler pod specification file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
1.1.6 Ensure that the scheduler pod specification file ownership is set to root:root. Scored 1 Pass IBM
1.1.7 Ensure that the etcd pod specification file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
1.1.8 Ensure that the etcd pod specification file ownership is set to root:root. Scored 1 Pass IBM
1.1.9 Ensure that the Container Network Interface file permissions are set to 644 or more restrictive. Not Scored 1 Pass IBM
1.1.10 Ensure that the Container Network Interface file ownership is set to root:root. Not Scored 1 Pass IBM
1.1.11 Ensure that the etcd data directory permissions are set to 700 or more restrictive. Scored 1 Pass IBM
1.1.12 Ensure that the etcd data directory ownership is set to etcd:etcd. Scored 1 Pass IBM
1.1.13 Ensure that the admin.conf file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
1.1.14 Ensure that the admin.conf file ownership is set to root:root. Scored 1 Pass IBM
1.1.15 Ensure that the scheduler.conf file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
1.1.16 Ensure that the scheduler.conf file ownership is set to root:root. Scored 1 Pass IBM
1.1.17 Ensure that the controller-manager.conf file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
1.1.18 Ensure that the controller-manager.conf file ownership is set to root:root. Scored 1 Pass IBM
1.1.19 Ensure that the Kubernetes PKI directory and file ownership is set to root:root. Scored 1 Pass IBM
1.1.20 Ensure that the Kubernetes PKI certificate file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
1.1.21 Ensure that the Kubernetes PKI key file permissions are set to 600. Scored 1 Pass IBM

1.2 API server

Section 1.2 API server benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
1.2.1 Ensure that the --anonymous-auth option is set to false. Not Scored 1 Fail IBM
1.2.2 Ensure that the --basic-auth-file option is not set. Scored 1 Pass IBM
1.2.3 Ensure that the --token-auth-file parameter is not set. Scored 1 Pass IBM
1.2.4 Ensure that the --kubelet-https option is set to true. Scored 1 Pass IBM
1.2.5 Ensure that the --kubelet-client-certificate and --kubelet-client-key options are set as appropriate. Scored 1 Pass IBM
1.2.6 Ensure that the --kubelet-certificate-authority option is set as appropriate. Scored 1 Pass IBM
1.2.7 Ensure that the --authorization-mode option is not set to AlwaysAllow. Scored 1 Pass IBM
1.2.8 Ensure that the --authorization-mode option includes Node. Scored 1 Pass IBM
1.2.9 Ensure that the --authorization-mode option includes RBAC. Scored 1 Pass IBM
1.2.10 Ensure that the admission control plug-in EventRateLimit is set. Not Scored 1 Fail IBM
1.2.11 Ensure that the admission control plug-in AlwaysAdmit is not set. Scored 1 Pass IBM
1.2.12 Ensure that the admission control plug-in AlwaysPullImages is set. Not Scored 1 Fail IBM
1.2.13 Ensure that the admission control plug-in SecurityContextDeny is set if PodSecurityPolicy is not used. Not Scored 1 Pass IBM
1.2.14 Ensure that the admission control plug-in ServiceAccount is set. Scored 1 Pass IBM
1.2.15 Ensure that the admission control plug-in NamespaceLifecycle is set. Scored 1 Pass IBM
1.2.16 Ensure that the admission control plug-in PodSecurityPolicy is set. Scored 1 Pass IBM
1.2.17 Ensure that the admission control plug-in NodeRestriction is set. Scored 1 Pass IBM
1.2.18 Ensure that the --insecure-bind-address option is not set. Scored 1 Pass IBM
1.2.19 Ensure that the --insecure-port option is set to 0. Scored 1 Pass IBM
1.2.20 Ensure that the --secure-port option is not set to 0. Scored 1 Pass IBM
1.2.21 Ensure that the --profiling option is set to false. Scored 1 Pass IBM
1.2.22 Ensure that the --audit-log-path option is set. Scored 1 Fail Shared
1.2.23 Ensure that the --audit-log-maxage option is set to 30 or as appropriate. Scored 1 Fail Shared
1.2.24 Ensure that the --audit-log-maxbackup option is set to 10 or as appropriate. Scored 1 Fail Shared
1.2.25 Ensure that the --audit-log-maxsize option is set to 100 or as appropriate. Scored 1 Fail Shared
1.2.26 Ensure that the --request-timeout option is set as appropriate. Scored 1 Pass IBM
1.2.27 Ensure that the --service-account-lookup option is set to true. Scored 1 Pass IBM
1.2.28 Ensure that the --service-account-key-file option is set as appropriate. Scored 1 Pass IBM
1.2.29 Ensure that the --etcd-certfile and --etcd-keyfile options are set as appropriate. Scored 1 Pass IBM
1.2.30 Ensure that the --tls-cert-file and --tls-private-key-file options are set as appropriate. Scored 1 Pass IBM
1.2.31 Ensure that the --client-ca-file option is set as appropriate. Scored 1 Pass IBM
1.2.32 Ensure that the --etcd-cafile option is set as appropriate. Scored 1 Pass IBM
1.2.33 Ensure that the --encryption-provider-config option is set as appropriate. Scored 1 Fail Shared
1.2.34 Ensure that encryption providers are appropriately configured. Scored 1 Fail Shared
1.2.35 Ensure that the API server makes use of only Strong Cryptographic Ciphers. Not Scored 1 Pass IBM

1.3 Controller manager

Section 1.3 Controller manager benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
1.3.1 Ensure that the --terminated-pod-gc-threshold option is set as appropriate. Scored 1 Pass IBM
1.3.2 Ensure that the --profiling option is set to false. Scored 1 Pass IBM
1.3.3 Ensure that the --use-service-account-credentials option is set to true. Scored 1 Pass IBM
1.3.4 Ensure that the --service-account-private-key-file option is set as appropriate. Scored 1 Pass IBM
1.3.5 Ensure that the --root-ca-file option is set as appropriate. Scored 1 Pass IBM
1.3.6 Ensure that the RotateKubeletServerCertificate option is set to true. Scored 2 Fail IBM
1.3.7 Ensure that the --bind-address option is set to 127.0.0.1. Scored 1 Pass IBM

1.4 Scheduler

Section 1.4 Scheduler benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
1.4.1 Ensure that the --profiling option is set to false. Scored 1 Pass IBM
1.4.2 Ensure that the --bind-address option is set to 127.0.0.1. Scored 1 Pass IBM

2 Etcd node configuration

Review the Etcd Node Configuration results of the version 1.5 CIS Kubernetes benchmark.

Section 2 Etcd Node Configuration benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
2.1 Ensure that the --cert-file and --key-file options are set as appropriate. Scored 1 Pass IBM
2.2 Ensure that the --client-cert-auth option is set to true. Scored 1 Pass IBM
2.3 Ensure that the --auto-tls option is not set to true. Scored 1 Pass IBM
2.4 Ensure that the --peer-cert-file and --peer-key-file options are set as appropriate. Scored 1 Pass IBM
2.5 Ensure that the --peer-client-cert-auth option is set to true. Scored 1 Pass IBM
2.6 Ensure that the --peer-auto-tls option is not set to true. Scored 1 Pass IBM
2.7 Ensure that a unique Certificate Authority is used for etcd. Not Scored 2 Pass IBM

3 Control plane configuration

Review the Control Plane Configuration results of the version 1.5 CIS Kubernetes benchmark.

3.1 Authentication and authorization

Section 3.1 Authentication and Authorization benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
3.1.1 Client certificate authentication should not be used for users. Not Scored 2 Pass Shared

3.2 Logging

Section 3.2 Logging benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
3.2.1 Ensure that a minimal audit policy is created. Scored 1 Fail Shared
3.2.2 Ensure that the audit policy covers key security concerns. Not Scored 2 Fail Shared

4 Worker node security configuration

Review the Worker Node Security Configuration results of the version 1.5 CIS Kubernetes benchmark.

4.1 Worker node configuration files

Section 4.1 Worker Node Configuration benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
4.1.1 Ensure that the kubelet service file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
4.1.2 Ensure that the kubelet service file ownership is set to root:root. Scored 1 Pass IBM
4.1.3 Ensure that the proxy kubeconfig file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
4.1.4 Ensure that the proxy kubeconfig file ownership is set to root:root. Scored 1 Pass IBM
4.1.5 Ensure that the kubelet.conf file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
4.1.6 Ensure that the kubelet.conf file ownership is set to root:root. Scored 1 Pass IBM
4.1.7 Ensure that the certificate authorities file permissions are set to 644 or more restrictive. Scored 1 Pass IBM
4.1.8 Ensure that the client certificate authorities file ownership is set to root:root. Scored 1 Pass IBM
4.1.9 Ensure that the kubelet configuration file has permissions set to 644 or more restrictive. Scored 1 Pass IBM
4.1.10 Ensure that the kubelet configuration file ownership is set to root:root. Scored 1 Pass IBM

4.2 Kubelet

Section 4.2 Kubelet benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
4.2.1 Ensure that the --anonymous-auth option is set to false. Scored 1 Pass IBM
4.2.2 Ensure that the --authorization-mode option is not set to AlwaysAllow. Scored 1 Pass IBM
4.2.3 Ensure that the --client-ca-file option is set as appropriate. Scored 1 Pass IBM
4.2.4 Ensure that the --read-only-port option is set to 0. Scored 1 Pass IBM
4.2.5 Ensure that the --streaming-connection-idle-timeout option is not set to 0. Scored 1 Pass IBM
4.2.6 Ensure that the --protect-kernel-defaults option is set to true. Scored 1 Fail IBM
4.2.7 Ensure that the --make-iptables-util-chains option is set to true. Scored 1 Pass IBM
4.2.8 Ensure that the --hostname-override option is not set. Not Scored 1 Fail IBM
4.2.9 Ensure that the --event-qps option is set to 0 or a level that ensures appropriate event capture. Not Scored 2 Pass IBM
4.2.10 Ensure that the --tls-cert-file and --tls-private-key-file options are set as appropriate. Scored 1 Pass IBM
4.2.11 Ensure that the --rotate-certificates option is not set to false. Scored 1 Pass IBM
4.2.12 Ensure that the RotateKubeletServerCertificate option is set to true. Scored 1 Fail IBM
4.2.13 Ensure that the kubelet makes use of only Strong Cryptographic Ciphers. Not Scored 1 Pass IBM

5 Kubernetes policies

Review the Kubernetes Policies results of the version 1.5 CIS Kubernetes benchmark.

5.1 RBAC and service accounts

Section 5.1 RBAC and Service Accounts benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
5.1.1 Ensure that the cluster-admin role is only used where required. Not Scored 1 Pass Shared
5.1.2 Minimize access to secrets. Not Scored 1 Fail Shared
5.1.3 Minimize wildcard use in Roles and ClusterRoles. Not Scored 1 Fail Shared
5.1.4 Minimize access to create pods. Not Scored 1 Pass Shared
5.1.5 Ensure that default service accounts are not actively used. Scored 1 Fail Shared
5.1.6 Ensure that Service Account Tokens are only mounted where necessary. Not Scored 1 Fail Shared

5.2 Pod Security Policies

Section 5.2 Pod Security Policies benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
5.2.1 Minimize the admission of privileged containers. Not Scored 1 Pass Shared
5.2.2 Minimize the admission of containers wanting to share the host process ID namespace. Scored 1 Pass Shared
5.2.3 Minimize the admission of containers wanting to share the host IPC namespace. Scored 1 Pass Shared
5.2.4 Minimize the admission of containers wanting to share the host network namespace. Scored 1 Pass Shared
5.2.5 Minimize the admission of containers with allowPrivilegeEscalation. Scored 1 Pass Shared
5.2.6 Minimize the admission of root containers. Not Scored 2 Pass Shared
5.2.7 Minimize the admission of containers with the NET_RAW capability. Not Scored 1 Pass Shared
5.2.8 Minimize the admission of containers with added capabilities. Not Scored 1 Pass Shared
5.2.9 Minimize the admission of containers with capabilities assigned. Not Scored 2 Pass Shared

5.3 Network policies and CNI

Section 5.3 Network policies and CNI benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
5.3.1 Ensure that the CNI in use supports network policies. Not Scored 1 Pass IBM
5.3.2 Ensure that all namespaces have network policies defined. Scored 2 Fail Shared

5.4 Secrets management

Section 5.4 Secrets management benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
5.4.1 Prefer using secrets as files over secrets as environment variables. Not Scored 1 Pass Shared
5.4.2 Consider external secret storage. Not Scored 2 Fail Shared

5.5 Extensible admission control

Section 5.5 Extensible admission control benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
5.5.1 Configure Image Provenance using ImagePolicyWebhook admission controller. Not Scored 2 Fail Shared

5.6 General policies

Section 5.6 General policies benchmark results
Section Recommendation Scored/Not Scored Level Result Responsibility
5.6.1 Create administrative boundaries between resources using namespaces. Not Scored 1 Pass Shared
5.6.2 Ensure that the seccomp profile is set to docker/default in your pod definitions. Not Scored 2 Fail Shared
5.6.3 Apply security context to your pods and containers. Not Scored 2 Fail Shared
5.6.4 The default namespace should not be used. Scored 2 Fail Shared

IBM remediations and explanations

Review information from IBM on the CIS Benchmark results.

Explanation and remediation
Section Remediation/Explanation
1.2.1 IBM Cloud Kubernetes Service utilizes RBAC for cluster protection, but allows anonymous discovery, which is considered reasonable per CIS Kubernetes Benchmark.
1.2.10 IBM Cloud Kubernetes Service does not enable the EventRateLimit admission controller since it is a Kubernetes alpha feature.
1.2.12 IBM Cloud Kubernetes Service does not enable the AlwaysPullImages admission controller since it overrides a container's imagePullPolicy and may impact performance.
1.2.22 IBM Cloud Kubernetes Service can optionally enable Kubernetes API server auditing.
1.2.23 IBM Cloud Kubernetes Service can optionally enable Kubernetes API server auditing.
1.2.24 IBM Cloud Kubernetes Service can optionally enable Kubernetes API server auditing.
1.2.25 IBM Cloud Kubernetes Service can optionally enable Kubernetes API server auditing.
1.2.33 IBM Cloud Kubernetes Service can optionally enable a Kubernetes Key Management Service (KMS) provider.
1.2.34 IBM Cloud Kubernetes Service can optionally enable a Kubernetes Key Management Service (KMS) provider.
1.3.6 IBM Cloud Kubernetes Service rotates certificates on every worker node reload or update.
3.2.1 IBM Cloud Kubernetes Service can optionally enable Kubernetes API server auditing.
3.2.2 IBM Cloud Kubernetes Service can optionally enable Kubernetes API server auditing.
4.2.6 IBM Cloud Kubernetes Service does not protect kernel defaults to allow customers to tune kernel parameters.
4.2.8 IBM Cloud Kubernetes Service ensures that the hostname matches the name issued by the infrastructure.
4.2.11 IBM Cloud Kubernetes Service rotates certificates on every worker node reload or update.
4.2.12 IBM Cloud Kubernetes Service rotates certificates on every worker node reload or update.
5.1.2 IBM Cloud Kubernetes Service deploys some system components that could have their Kubernetes secret access further restricted.
5.1.3 IBM Cloud Kubernetes Service deploys some system components that could have their Kubernetes resource access further restricted.
5.1.5 IBM Cloud Kubernetes Service does not set automountServiceAccountToken: false for each default service account.
5.1.6 IBM Cloud Kubernetes Service deploys some system components that could set automountServiceAccountToken: false.
5.2.1 IBM Cloud Kubernetes Service can optionally configure pod security policies.
5.2.2 IBM Cloud Kubernetes Service can optionally configure pod security policies.
5.2.3 IBM Cloud Kubernetes Service can optionally configure pod security policies.
5.2.4 IBM Cloud Kubernetes Service can optionally configure pod security policies.
5.2.5 IBM Cloud Kubernetes Service can optionally configure pod security policies.
5.2.6 IBM Cloud Kubernetes Service can optionally configure pod security policies.
5.2.7 IBM Cloud Kubernetes Service can optionally configure pod security policies.
5.2.8 IBM Cloud Kubernetes Service can optionally configure pod security policies.
5.2.9 IBM Cloud Kubernetes Service can optionally configure pod security policies.
5.3.2 IBM Cloud Kubernetes Service has a set of default Calico and Kubernetes network policies defined and additional network policies can optionally be added.
5.4.2 IBM Cloud Kubernetes Service can optionally enable a Kubernetes Key Management Service (KMS) provider.
5.5.1 IBM Cloud Kubernetes Service can optionally enable image security enforcement.
5.6.2 IBM Cloud Kubernetes Service does not annotate all pods with seccomp profiles.
5.6.3 IBM Cloud Kubernetes Service deploys some system components that do not set a pod or container securityContext.
5.6.4 IBM Cloud Kubernetes Service deploys some Kubernetes resources to the default names.