Cis Ocp V190 1.1.3

CIS Red Hat OpenShift Container Platform Benchmark v1.9.0 - Control 1.1.3

Profile Applicability

• Level: 1

Description

Ensure that the controller manager pod specification file has permissions of 600 or more restrictive.

Rationale

The controller manager pod specification file controls various parameters that set the behavior of the Controller Manager on the master node. You should restrict its file permissions to maintain the integrity of the file. The file should be writable by only the administrators on the system.

Impact

None.

Audit Procedure

OpenShift 4 deploys two controller managers: the OpenShift Controller manager and the Kube Controller manager.

The OpenShift Controller manager is managed as a deployment. The pod specification yaml for openshift-controller-manager is stored in etcd.

The Kube Controller manager is managed as a static pod. The pod specification file for the openshift-kube-controller-manager is created on control plane nodes at /etc/kubernetes/manifests/kube-controller-manager-pod.yaml. It is mounted via hostpath to the kube-controller-manager pods via /etc/kubernetes/static-pod-resources/kube-controller-manager-pod.yaml with permissions 0644.

To verify pod specification file permissions for the kube-controller-manager, run the following command.

for i in $( oc get pods -n openshift-kube-controller-manager -o name -l app=kube-controller-manager)
do
  oc exec  -n openshift-kube-controller-manager $i -- \
  stat -c %a /etc/kubernetes/static-pod-resources/kube-controller-manager-pod.yaml
done

Verify that the permissions are 600 or more restrictive.

Remediation

There is no remediation for updating the permissions of kube-controller-manager-pod.yaml. The file is owned by an OpenShift operator and any changes to the file will result in a degraded cluster state.

Please do not attempt to remediate the permissions of this file.

Default Value

By default, in OpenShift 4.14, the kube-controller-manager-pod.yaml has permissions of 600.

In older versions of OpenShift, the kube-controller-manager-pod.yaml has permissions of 644, and it not remediable. Please upgrade to OpenShift 4.14 when possible.

References

1. https://docs.openshift.com/container-platform/latest/architecture/control-plane.html#defining-masters_control-plane
2. https://github.com/openshift/library-go/commit/19a42d2bae8ba68761cfad72bf764e10d275ad6e
3. https://kubernetes.io/docs/reference/command-line-tools-reference/kube-controller-manager/

CIS Controls

MITRE ATT&CK Mappings

Profile

Level 1 (Manual)