Cis Ocp V190 1.1.12

CIS Red Hat OpenShift Container Platform Benchmark v1.9.0 - Control 1.1.12

Profile Applicability

• Level: 1

Description

Ensure that the etcd data directory ownership is set to root:root.

Rationale

etcd is a highly-available key-value store used by Kubernetes deployments for persistent storage of all of its REST API objects. This data directory should be protected from any unauthorized reads or writes. It should be owned by root:root.

In the OpenShift Container Platform, the ownership and permissions of the etcd data directory (usually located at /var/lib/etcd) are handled by the cluster-etcd-operator. This automation ensures the correct and secure configuration is maintained.

NOTE: The only users that exist on an RHCOS OpenShift node are root and core. This is intentional, as regular management of the underlying RHCOS cluster nodes is designed to be performed via the OpenShift API itself. The core user is a member of the wheel group, which gives it permission to use sudo for running privileged commands. Adding additional users at the node level is highly discouraged.

Impact

None

Audit Procedure

In OpenShift 4, etcd members are deployed on the master nodes as static pods. The etcd database is stored on the master nodes in /var/lib/etcd and mounted to the etcd-member container via the host path mount data-dir with the same filesystem path (/var/lib/etcd). The ownership for this directory on the etcd-member container and on the container host is root:root.

Starting with OCP 4.4, etcd is managed by the cluster-etcd-operator. The etcd operator will help to automate restoration of master nodes. There is also a new etcdctl container in the etcd static pod for quick debugging. cluster-admin rights are required to exec into etcd containers.

Run the following command.

for i in $(oc get pods -n openshift-etcd -l app=etcd -oname); do oc exec -n openshift-etcd -c etcd $i -- stat -c %U:%G /var/lib/etcd/member; done

Verify that the ownership is set to root:root.

Remediation

No remediation required; file ownership is managed by the operator.

Default Value

By default, in OpenShift 4, etcd data directory ownership is set to root:root.

References

1. https://docs.openshift.com/container-platform/4.3/architecture/control-plane.html#defining-masters_control-plane
2. https://etcd.io/#data-dir
3. https://kubernetes.io/docs/tasks/administer-cluster/configure-upgrade-etcd/

CIS Controls

MITRE ATT&CK Mappings

Profile

Level 1 (Manual)