Version 1.25 CIS Kubernetes benchmark
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 1.25. For more information or help understanding the benchmark, see Using the benchmark.
Kubernetes version 1.25 is no longer supported. Update your cluster to at least version 1.26 as soon as possible.
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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | 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 | Recommendation | Scored? | Level | Result | Responsibility |
|---|---|---|---|---|---|
| 5.5.1 | Configure Image Provenance using ImagePolicyWebhook admission controller. |
Not Scored | 2 | Fail | Shared |
5.6 General policies
| Section | Recommendation | 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.
| 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. |
| 1.2.13 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes pod security policies. |
| 1.2.16 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes pod security policies. |
| 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 admission, which is similar to the unsupported Kubernetes pod security policies. |
| 5.2.2 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes pod security policies. |
| 5.2.3 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes pod security policies. |
| 5.2.4 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes pod security policies. |
| 5.2.5 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes pod security policies. |
| 5.2.6 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes pod security policies. |
| 5.2.7 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes pod security policies. |
| 5.2.8 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes pod security policies. |
| 5.2.9 | IBM Cloud Kubernetes Service can optionally configure Pod security admission, which is similar to the unsupported Kubernetes 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. |