cis-k8s-v1111-2-4

name	cis-k8s-v1111-2.4
description	Ensure that the --auto-tls argument is not set to true (Automated)
category	cis-k8s
version	1.11.1
author	cyberstrike-official
tags	["cis","kubernetes","etcd","encryption","tls","certificates","peer-authentication"]
cis_id	2.4
cis_benchmark	CIS Kubernetes Benchmark v1.11.1
tech_stack	["kubernetes"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

2.4 Ensure that the --auto-tls argument is not set to true (Automated)

Profile Applicability

• Level 1 - Master Node

Description

Do not use self-signed certificates for TLS.

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 not be available to unauthenticated clients. You should enable the client authentication via valid certificates to secure the access to the etcd service.

Impact

Clients will not be able to use self-signed certificates for TLS.

Audit

Run the following command on the etcd server node:

ps -ef | grep etcd

Verify that if the --auto-tls argument exists, it is not set to true.

Remediation

Edit the etcd pod specification file /etc/kubernetes/manifests/etcd.yaml on the master node and either remove the --auto-tls parameter or set it to false.

--auto-tls=false

Default Value

By default, --auto-tls 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#auto-tls

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	3.11 Encrypt Sensitive Data at Rest		x	x
v7	14.4 Encrypt All Sensitive Information in Transit		x	x