Cis Ocp V160 1.3.4

CIS Red Hat OpenShift Container Platform Benchmark v1.6.0 - Control 1.3.4

Profile Applicability

• Level: 1

Description

Allow pods to verify the API server's serving certificate before establishing connections.

Rationale

Processes running within pods that need to contact the API server must verify the API server's serving certificate. Failing to do so could be a subject to man-in-the-middle attacks.

Providing the root certificate for the API server's serving certificate to the controller manager with the --root-ca-file argument allows the controller manager to inject the trusted bundle into pods so that they can verify TLS connections to the API server.

Impact

OpenShift clusters manage and maintain certificate authorities and certificates for cluster components.

Audit Procedure

Certificates for OpenShift platform components are automatically created and rotated by the OpenShift Container Platform.

Run the following command:

oc get configmaps config -n openshift-kube-controller-manager -ojson | \
  jq -r '.data["config.yaml"]' | \
  jq -r '.extendedArguments["root-ca-file"][]'

Verify that the --root-ca-file argument exists and is set to /etc/kubernetes/static-pod-resources/configmaps/serviceaccount-ca/ca-bundle.crt.

Remediation

None.

Default Value

By default, OpenShift sets the Kubernetes Controller Manager root-ca-file to /etc/kubernetes/static-pod-resources/configmaps/serviceaccount-ca/ca-bundle.crt.

Certificates for OpenShift platform components are automatically created and rotated by the OpenShift Container Platform.

References

1. https://docs.openshift.com/container-platform/4.13/operators/operator-reference.html
2. https://docs.openshift.com/container-platform/latest/operators/operator-reference.html#cluster-openshift-controller-manager-operator_cluster-operators-ref
3. https://docs.openshift.com/container-platform/4.13/security/certificate_types_descriptions/control-plane-certificates.html
4. https://github.com/openshift/cluster-kube-controller-manager-operator/blob/release-4.5/bindata/bootkube/bootstrap-manifests/kube-controller-manager-pod.yaml
5. https://github.com/openshift/cluster-kube-controller-manager-operator/blob/release-4.5/bindata/bootkube/config/bootstrap-config-overrides.yaml
6. https://github.com/openshift/cluster-kube-controller-manager-operator/blob/release-4.5/bindata/v4.1.0/kube-controller-manager/kubeconfig-cm.yaml
7. https://kubernetes.io/docs/reference/command-line-tools-reference/kube-controller-manager/
8. https://github.com/kubernetes/kubernetes/issues/11000

CIS Controls

MITRE ATT&CK Mappings

Profile

Level 1 (Manual)