cis-aks-v170-3-1-1

name	cis-aks-v170-3.1.1
description	Ensure that the kubeconfig file permissions are set to 644 or more restrictive (Automated)
category	cis-aks
version	1.7.0
author	cyberstrike-official
tags	["cis","aks","kubernetes","azure","worker-node","file-permissions","kubeconfig"]
cis_id	3.1.1
cis_benchmark	CIS Azure Kubernetes Service (AKS) Benchmark v1.7.0
tech_stack	["kubernetes","azure","aks"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

3.1.1 Ensure that the kubeconfig file permissions are set to 644 or more restrictive (Automated)

Profile Applicability

• Level 1

Description

If kubelet is running, and if it is configured by a kubeconfig file, ensure that the proxy kubeconfig file has permissions of 644 or more restrictive.

Rationale

The kubelet kubeconfig file controls various parameters of the kubelet service in the worker node. You should restrict its file permissions to maintain the integrity of the file. The file should be writable by only the administrators on the system.

It is possible to run kubelet with the kubeconfig parameters configured as a Kubernetes ConfigMap instead of a file. In this case, there is no proxy kubeconfig file.

Impact

None.

Audit Procedure

Method 1

SSH to the worker nodes.

To check to see if the Kubelet Service is running:

sudo systemctl status kubelet

The output should return Active: active (running) since...

Run the following command on each node to find the appropriate kubeconfig file:

ps -ef | grep kubelet

The output of the above command should return something similar to --kubeconfig /var/lib/kubelet/kubeconfig which is the location of the kubeconfig file.

Run this command to obtain the kubeconfig file permissions:

stat -c %a /var/lib/kubelet/kubeconfig

The output of the above command gives you the kubeconfig file's permissions.

Verify that if a file is specified and it exists, the permissions are 644 or more restrictive.

Method 2

Create and Run a Privileged Pod.

You will need to run a pod that is privileged enough to access the host's file system. This can be achieved by deploying a pod that uses the hostPath volume to mount the node's file system into the pod.

Here's an example of a simple pod definition that mounts the root of the host to /host within the pod:

apiVersion: v1
kind: Pod
metadata:
   

  
      
      
         
         
  
      
       
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