Cis Ocp V170 1.1.1

CIS Red Hat OpenShift Container Platform Benchmark v1.7.0 - Control 1.1.1

Profile Applicability

• Level: 1

Description

Ensure that the API server pod specification file has permissions of 600 or more restrictive.

Rationale

The API server pod specification file controls various parameters that set the behavior of the API server. You should restrict its file permissions to maintain the integrity of the file. The file should be writable only by the administrators on the system.

Impact

None.

Audit Procedure

OpenShift 4 deploys two API servers: the OpenShift API server and the Kube API server. The OpenShift API server delegates requests for Kubernetes objects to the Kube API server. The OpenShift API server is managed as a deployment. The pod specification yaml for openshift-apiserver is stored in etcd. The Kube API Server is managed as a static pod. The pod specification file for the kube-apiserver is created on the control plane nodes at /etc/kubernetes/manifests/kube-apiserver-pod.yaml. The kube-apiserver is mounted via hostpath to the kube-apiserver pods via /etc/kubernetes/static-pod-resources/kube-apiserver-pod.yaml with permissions 600.

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

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

Verify that the permissions are 600 or more restrictive.

Remediation

There is no remediation for updating the permissions of kube-apiserver-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-apiserver-pod.yaml has permissions of 600.

In older versions of OpenShift, the kube-apiserver-pod.yaml has permissions of 644, and is 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://kubernetes.io/docs/reference/command-line-tools-reference/kube-apiserver/
3. https://github.com/openshift/library-go/commit/19a42d2bae8ba68761cfad72bf764e10d275ad6e

CIS Controls

MITRE ATT&CK Mappings

Profile

Level 1 (Manual)