cis-k8s-v200-4-1-10

name	cis-k8s-v200-4.1.10
description	If the kubelet config.yaml configuration file is being used validate file ownership is set to root:root (Automated)
category	cis-k8s
version	2.0.0
author	cyberstrike-official
tags	["cis","kubernetes","worker-node","config-files","file-ownership","kubelet-config"]
cis_id	4.1.10
cis_benchmark	CIS Kubernetes Benchmark v2.0.0
tech_stack	["kubernetes"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

4.1.10 If the kubelet config.yaml configuration file is being used validate file ownership is set to root:root (Automated)

Profile Applicability

• Level 1 - Worker Node

Description

Ensure that if the kubelet refers to a configuration file with the --config argument, that file is owned by root:root.

Rationale

The kubelet reads various parameters, including security settings, from a config file specified by the --config argument. If this file is specified you should restrict its file permissions to maintain the integrity of the file. The file should be owned by root:root.

Impact

None

Audit

Automated AAC auditing has been modified to allow CIS-CAT to input a variable for the <PATH>/<FILENAME> of the kubelet config yaml file.

Please set $kubelet_config_yaml=<PATH><filename> based on the file location on your system.

For example:

export kubelet_config_yaml=/var/lib/kubelet/config.yaml

To perform the audit manually: Run the below command (based on the file location on your system) on the each worker node. For example,

stat -c %U:%G /var/lib/kubelet/config.yaml

Verify that the ownership is set to root:root.

Remediation

Run the following command (using the config file location identified in the Audit step)

chown root:root /etc/kubernetes/kubelet.conf

Default Value

By default, /var/lib/kubelet/config.yaml file as set up by kubeadm is owned by root:root.

References

1. https://kubernetes.io/docs/tasks/administer-cluster/kubelet-config-file/

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	5.4 Restrict Administrator Privileges to Dedicated Administrator Accounts - Restrict administrator privileges to dedicated administrator accounts on enterprise assets. Conduct general computing activities, such as internet browsing, email, and productivity suite use, from the user's primary, non-privileged account.