4.13 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 Red Hat OpenShift on IBM Cloud version 4.13. 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 | 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 | Recommendation | Scored/Not Scored | Level | Result | Responsibility |
|---|---|---|---|---|---|
| 1.2.1 | Ensure that the --anonymous-auth argument is set to false |
Not Scored | 1 | Fail | IBM |
| 1.2.2 | Ensure that the --basic-auth-file argument 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 argument is set to true |
Scored | 1 | Pass | IBM |
| 1.2.5 | Ensure that the --kubelet-client-certificate and --kubelet-client-key arguments are set as appropriate |
Scored | 1 | Pass | IBM |
| 1.2.6 | Ensure that the --kubelet-certificate-authority argument is set as appropriate |
Scored | 1 | Pass | IBM |
| 1.2.7 | Ensure that the --authorization-mode argument is not set to AlwaysAllow |
Scored | 1 | Pass | IBM |
| 1.2.8 | Ensure that the --authorization-mode argument includes Node |
Scored | 1 | Pass | IBM |
| 1.2.9 | Ensure that the --authorization-mode argument 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 argument is not set |
Scored | 1 | Pass | IBM |
| 1.2.19 | Ensure that the --insecure-port argument is set to 0 |
Scored | 1 | Pass | IBM |
| 1.2.20 | Ensure that the --secure-port argument is not set to 0 |
Scored | 1 | Pass | IBM |
| 1.2.21 | Ensure that the --profiling argument is set to false |
Scored | 1 | Pass | IBM |
| 1.2.22 | Ensure that the --audit-log-path argument is set |
Scored | 1 | Fail | Shared |
| 1.2.23 | Ensure that the --audit-log-maxage argument is set to 30 or as appropriate |
Scored | 1 | Fail | Shared |
| 1.2.24 | Ensure that the --audit-log-maxbackup argument is set to 10 or as appropriate |
Scored | 1 | Fail | Shared |
| 1.2.25 | Ensure that the --audit-log-maxsize argument is set to 100 or as appropriate |
Scored | 1 | Fail | Shared |
| 1.2.26 | Ensure that the --request-timeout argument is set as appropriate |
Scored | 1 | Pass | IBM |
| 1.2.27 | Ensure that the --service-account-lookup argument is set to true |
Scored | 1 | Pass | IBM |
| 1.2.28 | Ensure that the --service-account-key-file argument is set as appropriate |
Scored | 1 | Pass | IBM |
| 1.2.29 | Ensure that the --etcd-certfile and --etcd-keyfile arguments are set as appropriate |
Scored | 1 | Pass | IBM |
| 1.2.30 | Ensure that the --tls-cert-file and --tls-private-key-file arguments are set as appropriate |
Scored | 1 | Pass | IBM |
| 1.2.31 | Ensure that the --client-ca-file argument is set as appropriate |
Scored | 1 | Pass | IBM |
| 1.2.32 | Ensure that the --etcd-cafile argument is set as appropriate |
Scored | 1 | Pass | IBM |
| 1.2.33 | Ensure that the --encryption-provider-config argument 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 only makes use of Strong Cryptographic Ciphers | Not Scored | 1 | Pass | IBM |
1.3 Controller manager
| Section | Recommendation | Scored/Not Scored | Level | Result | Responsibility |
|---|---|---|---|---|---|
| 1.3.1 | Ensure that the --terminated-pod-gc-threshold argument is set as appropriate |
Scored | 1 | Pass | IBM |
| 1.3.2 | Ensure that the --profiling argument is set to false |
Scored | 1 | Pass | IBM |
| 1.3.3 | Ensure that the --use-service-account-credentials argument is set to true |
Scored | 1 | Pass | IBM |
| 1.3.4 | Ensure that the --service-account-private-key-file argument is set as appropriate |
Scored | 1 | Pass | IBM |
| 1.3.5 | Ensure that the --root-ca-file argument is set as appropriate |
Scored | 1 | Pass | IBM |
| 1.3.6 | Ensure that the RotateKubeletServerCertificate argument is set to true |
Scored | 2 | Pass | IBM |
| 1.3.7 | Ensure that the --bind-address argument is set to 127.0.0.1 |
Scored | 1 | Pass | IBM |
1.4 Scheduler
| Section | Recommendation | Scored/Not Scored | Level | Result | Responsibility |
|---|---|---|---|---|---|
| 1.4.1 | Ensure that the --profiling argument is set to false |
Scored | 1 | Pass | IBM |
| 1.4.2 | Ensure that the --bind-address argument is set to 127.0.0.1 |
Scored | 1 | Pass | IBM |
2 Etcd node configuration
| Section | Recommendation | Scored/Not Scored | Level | Result | Responsibility |
|---|---|---|---|---|---|
| 2.1 | Ensure that the --cert-file and --key-file arguments are set as appropriate |
Scored | 1 | Pass | IBM |
| 2.2 | Ensure that the --client-cert-auth argument is set to true |
Scored | 1 | Pass | IBM |
| 2.3 | Ensure that the --auto-tls argument is not set to true |
Scored | 1 | Pass | IBM |
| 2.4 | Ensure that the --peer-cert-file and --peer-key-file arguments are set as appropriate |
Scored | 1 | Pass | IBM |
| 2.5 | Ensure that the --peer-client-cert-auth argument is set to true |
Scored | 1 | Pass | IBM |
| 2.6 | Ensure that the --peer-auto-tls argument 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
3.1 Authentication and authorization
| 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 | 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 | 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 | Recommendation | Scored/Not Scored | Level | Result | Responsibility |
|---|---|---|---|---|---|
| 4.2.1 | Ensure that the --anonymous-auth argument is set to false |
Scored | 1 | Pass | IBM |
| 4.2.2 | Ensure that the --authorization-mode argument is not set to AlwaysAllow |
Scored | 1 | Pass | IBM |
| 4.2.3 | Ensure that the --client-ca-file argument is set as appropriate |
Scored | 1 | Pass | IBM |
| 4.2.4 | Ensure that the --read-only-port argument is set to 0 |
Scored | 1 | Pass | IBM |
| 4.2.5 | Ensure that the --streaming-connection-idle-timeout argument is not set to 0 |
Scored | 1 | Pass | IBM |
| 4.2.6 | Ensure that the --protect-kernel-defaults argument is set to true |
Scored | 1 | Fail | IBM |
| 4.2.7 | Ensure that the --make-iptables-util-chains argument is set to true |
Scored | 1 | Pass | IBM |
| 4.2.8 | Ensure that the --hostname-override argument is not set |
Not Scored | 1 | Fail | IBM |
| 4.2.9 | Ensure that the --event-qps argument is set to 0 or a level which ensures appropriate event capture |
Not Scored | 2 | Pass | IBM |
| 4.2.10 | Ensure that the --tls-cert-file and --tls-private-key-file arguments are set as appropriate |
Scored | 1 | Pass | IBM |
| 4.2.11 | Ensure that the --rotate-certificates argument is not set to false |
Scored | 1 | Pass | IBM |
| 4.2.12 | Ensure that the RotateKubeletServerCertificate argument is set to true |
Scored | 1 | Pass | IBM |
| 4.2.13 | Ensure that the kubelet only makes use of 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/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 | 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 wishing to share the host process ID namespace | Scored | 1 | Pass | Shared |
| 5.2.3 | Minimize the admission of containers wishing to share the host IPC namespace | Scored | 1 | Pass | Shared |
| 5.2.4 | Minimize the admission of containers wishing 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/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 | Recommendation | Scored/Not Scored | Level | Result | Responsibility |
|---|---|---|---|---|---|
| 5.4.1 | Prefer using secrets as files over secrets as environment variables | Not Scored | 1 | Fail | Shared |
| 5.4.2 | Consider external secret storage | Not Scored | 2 | Fail | Shared |
5.5 Extensible admission control
| 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 | 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 | Pass | Shared |
IBM remediations and explanations
| Section | Remediation/Explanation |
|---|---|
| 1.2.1 | Red Hat OpenShift on IBM Cloud utilizes RBAC for cluster protection, but allows anonymous discovery, which is considered reasonable per CIS Kubernetes Benchmark. |
| 1.2.10 | Red Hat OpenShift on IBM Cloud does not enable the EventRateLimit admission controller since it is a Kubernetes
alpha feature. |
| 1.2.12 | Red Hat OpenShift on IBM Cloud does not enable the AlwaysPullImages admission controller since it overrides a
container's imagePullPolicy and may impact performance. |
| 1.2.13 | Red Hat OpenShift on IBM Cloud supports OpenShift security context constraints and Kubernetes pod security admissionwhich are similar to the deprecated Kubernetes pod security policies. |
| 1.2.16 | Red Hat OpenShift on IBM Cloud supports OpenShift security context constraints and Kubernetes pod security admissionwhich are similar to the deprecated Kubernetes pod security policies. |
| 1.2.22 | Red Hat OpenShift on IBM Cloud can optionally enable Kubernetes API server auditing. |
| 1.2.23 | Red Hat OpenShift on IBM Cloud can optionally enable Kubernetes API server auditing. |
| 1.2.24 | Red Hat OpenShift on IBM Cloud can optionally enable Kubernetes API server auditing. |
| 1.2.25 | Red Hat OpenShift on IBM Cloud can optionally enable Kubernetes API server auditing. |
| 1.2.33 | Red Hat OpenShift on IBM Cloud can optionally enable a Kubernetes Key Management Service (KMS) provider. |
| 1.2.34 | Red Hat OpenShift on IBM Cloud can optionally enable a Kubernetes Key Management Service (KMS) provider. |
| 3.2.1 | Red Hat OpenShift on IBM Cloud can optionally enable Kubernetes API server auditing. |
| 3.2.2 | Red Hat OpenShift on IBM Cloud can optionally enable Kubernetes API server auditing. |
| 4.2.6 | Red Hat OpenShift on IBM Cloud does not protect kernel defaults to allow customers to tune kernel parameters. |
| 4.2.8 | Red Hat OpenShift on IBM Cloud ensures that the hostname matches the name issued by the infrastructure. |
| 5.1.2 | Red Hat OpenShift on IBM Cloud deploys some system components that could have their Kubernetes secret access further restricted. |
| 5.1.3 | Red Hat OpenShift on IBM Cloud deploys some system components that could have their Kubernetes resource access further restricted. |
| 5.1.5 | Red Hat OpenShift on IBM Cloud does not set automountServiceAccountToken: false for each default service account. |
| 5.1.6 | Red Hat OpenShift on IBM Cloud deploys some system components that could set automountServiceAccountToken: false. |
| 5.2.1 | Red Hat OpenShift on IBM Cloud can optionally configure OpenShift security context constraints and Kubernetes pod security admission which are similar to the deprecated Kubernetes pod security policies. |
| 5.2.2 | Red Hat OpenShift on IBM Cloud can optionally configure OpenShift security context constraints and Kubernetes pod security admission which are similar to the deprecated Kubernetes pod security policies. |
| 5.2.3 | Red Hat OpenShift on IBM Cloud can optionally configure OpenShift security context constraints and Kubernetes pod security admissionwhich are similar to the deprecated Kubernetes pod security policies. |
| 5.2.4 | Red Hat OpenShift on IBM Cloud can optionally configure OpenShift security context constraints and Kubernetes pod security admissionwhich are similar to the deprecated Kubernetes pod security policies. |
| 5.2.5 | Red Hat OpenShift on IBM Cloud can optionally configure OpenShift security context constraints and Kubernetes pod security admissionwhich are similar to the deprecated Kubernetes pod security policies. |
| 5.2.6 | Red Hat OpenShift on IBM Cloud can optionally configure OpenShift security context constraints and Kubernetes pod security admissionwhich are similar to the deprecated Kubernetes pod security policies. |
| 5.2.7 | Red Hat OpenShift on IBM Cloud can optionally configure OpenShift security context constraints and Kubernetes pod security admissionwhich are similar to the deprecated Kubernetes pod security policies. |
| 5.2.8 | Red Hat OpenShift on IBM Cloud can optionally configure OpenShift security context constraints and Kubernetes pod security admissionwhich are similar to the deprecated Kubernetes pod security policies. |
| 5.2.9 | Red Hat OpenShift on IBM Cloud can optionally configure OpenShift security context constraints and Kubernetes pod security admissionwhich are similar to the deprecated Kubernetes pod security policies. |
| 5.3.2 | Red Hat OpenShift on IBM Cloud has a set of default Calico network policies defined and additional network policies can optionally be added. |
| 5.4.1 | Red Hat OpenShift on IBM Cloud deploys some system components that could prefer using secrets as files over secrets as environment variables. |
| 5.4.2 | Red Hat OpenShift on IBM Cloud can optionally enable a Kubernetes Key Management Service (KMS) provider. |
| 5.5.1 | Red Hat OpenShift on IBM Cloud can optionally enable image security enforcement. |
| 5.6.2 | Red Hat OpenShift on IBM Cloud does not annotate all pods with seccomp profiles. |
| 5.6.3 | Red Hat OpenShift on IBM Cloud deploys some system components that do not set a pod or container securityContext. |