cis-k8s-v1120-3-1-2

name	cis-k8s-v1120-3.1.2
description	Service account token authentication should not be used for users (Manual)
category	cis-k8s
version	1.12.0
author	cyberstrike-official
tags	["cis","kubernetes","control-plane-config","authentication"]
cis_id	3.1.2
cis_benchmark	CIS Kubernetes Benchmark v1.12.0
tech_stack	["kubernetes"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

CIS Kubernetes Benchmark v1.12.0 - Control 3.1.2

Profile Applicability

• Level: 1 - Master Node

Description

Kubernetes provides service account tokens which are intended for use by workloads running in the Kubernetes cluster, for authentication to the API server.

These tokens are not designed for use by end-users and do not provide for features such as revocation or expiry, making them insecure. A newer version of the feature (Bound service account token volumes) does introduce expiry but still does not allow for specific revocation.

Rationale

With any authentication mechanism the ability to revoke credentials if they are compromised or no longer required, is a key control. Service account token authentication does not allow for this due to the use of JWT tokens as an underlying technology.

Impact

External mechanisms for authentication generally require additional software to be deployed.

Audit Procedure

Review user access to the cluster and ensure that users are not making use of service account token authentication.

Remediation

Alternative mechanisms provided by Kubernetes such as the use of OIDC should be implemented in place of service account tokens.

Default Value

Service account token authentication is enabled by default.

References

None

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	6.2 Establish an Access Revoking Process
v7	16.7 Establish Process for Revoking Access

Profile

Level 1 - Master Node (Manual)