cis-ocp-v190-1.3.3

CIS Red Hat OpenShift Container Platform Benchmark v1.9.0 - Control 1.3.3

Profile Applicability

• Level: 1

Description

Explicitly set a service account private key file for service accounts on the controller manager.

Rationale

To ensure that keys for service account tokens can be rotated as needed, a separate public/private key pair should be used for signing service account tokens. The private key should be specified to the controller manager with --service-account-private-key-file as appropriate.

Impact

You would need to securely maintain the key file and rotate the keys based on your organization's key rotation policy.

Audit Procedure

OpenShift starts the Kubernetes Controller Manager with service-account-private-key-file set to /etc/kubernetes/static-pod-resources/secrets/service-account-private-key/service-account.key.

The bootstrap configuration and overrides are available here:

• kube-controller-manager-pod
• bootstrap-config-overrides

Run the following command:

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

Verify that the following is returned:

/etc/kubernetes/static-pod-resources/secrets/service-account-private-key/service-account.key

Remediation

None.

Default Value

By default, OpenShift starts the controller manager with service-account-private-key-file set to /etc/kubernetes/static-pod-resources/secrets/service-account-private-key/service-account.key. OpenShift manages the service account credentials for the scheduler automatically.

References

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

CIS Controls

MITRE ATT&CK Mappings

Profile

Level 1 (Manual)