cis-k8s-v1110-1-2-30

name	cis-k8s-v1110-1.2.30
description	Ensure that the --service-account-extend-token-expiration parameter is set to false (Automated)
category	cis-k8s
version	1.11.0
author	cyberstrike-official
tags	["cis","kubernetes","control-plane","api-server","service-account-extend-token-expiration","token-security","authentication"]
cis_id	1.2.30
cis_benchmark	CIS Kubernetes Benchmark v1.11.0
tech_stack	["kubernetes"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

1.2.30 Ensure that the --service-account-extend-token-expiration parameter is set to false (Automated)

Profile Applicability

• Level 1 - Master Node

Description

By default Kubernetes extends service account token lifetimes to one year to aid in transition from the legacy token settings.

Rationale

This default setting is not ideal for security as it ignores other settings related to maximum token lifetime and means that a lost or stolen credential could be valid for an extended period of time.

Impact

Disabling this setting means that the service account token expiry set in the cluster will be enforced, and service account tokens will expire at the end of that time frame.

Audit

Run the following command on the Control Plane node:

ps -ef | grep kube-apiserver

Verify that the --service-account-extend-token-expiration argument is set to false.

Remediation

Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the Control Plane node and set the --service-account-extend-token-expiration parameter to false.

--service-account-extend-token-expiration=false

Default Value

By default, this parameter is set to true.

References

1. https://kubernetes.io/docs/reference/command-line-tools-reference/kube-apiserver/

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	10.5 Enable Anti-Exploitation Features		*	*
v7	5.1 Establish Secure Configurations	*	*	*