Cis Ocp V190 2.5

CIS Red Hat OpenShift Container Platform Benchmark v1.9.0 - Control 2.5

Profile Applicability

• Level: 1

Description

etcd should be configured for peer authentication.

Rationale

etcd is a highly-available key value store used by Kubernetes deployments for persistent storage of all of its REST API objects. These objects are sensitive in nature and should be accessible only by authenticated etcd peers in the etcd cluster.

Impact

All peers attempting to communicate with the etcd server require a valid client certificate for authentication.

Audit Procedure

OpenShift uses X.509 certificates to provide secure communication to etcd. OpenShift generates these files and sets the arguments appropriately. etcd certificates are used for encrypted communication between etcd member peers, as well as encrypted client traffic. Peer certificates are generated and used for communication between etcd members.

OpenShift installs etcd as static pods on control plane nodes, and mounts the configuration files from /etc/etcd/ on the host. The etcd.conf file includes peer-client-cert-auth configurations as referenced in /etc/etcd/etcd.conf.

Run the following command:

for i in $(oc get pods -oname -n openshift-etcd)
do
    oc exec -n openshift-etcd -c etcd $i -- \
      ps -o command= -C etcd | sed 's/.*\(--peer-client-cert-auth=[^ ]*\).*/\1/'
done

Verify that the --peer-client-cert-auth argument is set to true for each etcd member.

Remediation

This setting is managed by the cluster etcd operator. No remediation required.

Default Value

By default, --peer-client-cert-auth argument is set to true.

References

1. https://docs.openshift.com/container-platform/latest/security/certificate_types_descriptions/etcd-certificates.html
2. https://github.com/openshift/cluster-etcd-operator
3. https://github.com/openshift/cluster-etcd-operator/blob/release-4.5/bindata/etcd/pod.yaml#L154-L167
4. https://github.com/openshift/cluster-etcd-operator/blob/release-4.5/bindata/etcd/pod.yaml#L154-L167
5. https://etcd.io/
6. https://kubernetes.io/docs/tasks/administer-cluster/configure-upgrade-etcd/
7. https://etcd.io/#peer-client-cert-auth

CIS Controls

MITRE ATT&CK Mappings

Profile

Level 1 (Manual)