cis-k8s-v1110-2-6

name	cis-k8s-v1110-2.6
description	Ensure that the --peer-client-cert-auth argument is set to true (Automated)
category	cis-k8s
version	1.11.0
author	cyberstrike-official
tags	["cis","kubernetes","etcd","peer-auth","tls"]
cis_id	2.6
cis_benchmark	CIS Kubernetes Benchmark v1.11.0
tech_stack	["kubernetes"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

2.6 Ensure that the --peer-client-cert-auth argument is set to true (Automated)

Profile Applicability

• Level 1 - Master Node

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 will require a valid client certificate for authentication.

Audit

Run the following command on the etcd server node:

ps -ef | grep etcd

Verify that the --peer-client-cert-auth argument is set to true. Note: This recommendation is applicable only for etcd clusters. If you are using only one etcd server in your environment then this recommendation is not applicable.

Remediation

Edit the etcd pod specification file /etc/kubernetes/manifests/etcd.yaml on the master node and set the below parameter.

--peer-client-cert-auth=true

Default Value

Note: This recommendation is applicable only for etcd clusters. If you are using only one etcd server in your environment then this recommendation is not applicable.

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

References

1. https://coreos.com/etcd/docs/latest/op-guide/security.html
2. https://kubernetes.io/docs/admin/etcd/
3. https://coreos.com/etcd/docs/latest/op-guide/configuration.html#peer-client-cert-auth

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	3.3 Configure Data Access Control Lists	X	X	X
v7	14.6 Protect Information through Access Control Lists	X	X	X