| name | cis-gke-v170-3.1.3 |
| description | Ensure that the kubelet configuration file has permissions set to 644 (Automated) |
| category | cis-gke |
| version | 1.7.0 |
| author | cyberstrike-official |
| tags | ["cis","gke","kubernetes","gcp","worker-nodes","configuration-files","permissions","ownership","kubeconfig","kubelet"] |
| cis_id | 3.1.3 |
| cis_benchmark | CIS Google Kubernetes Engine (GKE) Benchmark v1.7.0 |
| tech_stack | ["kubernetes","gcp","gke"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
3.1.3 Ensure that the kubelet configuration file has permissions set to 644 (Automated)
Profile Applicability
Description
Ensure that if the kubelet configuration file exists, it has permissions of 644.
Rationale
The kubelet reads various parameters, including security settings, from a config file specified by the --config argument. If this file exists, 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.
Impact
Overly permissive file access increases security risk to the platform.
Audit
Using Google Cloud Console
- Go to Kubernetes Engine by visiting https://console.cloud.google.com/kubernetes/list
- Click on the desired cluster to open the Details page, then click on the desired Node pool to open the Node pool Details page
- Note the name of the desired node
- Go to VM Instances by visiting https://console.cloud.google.com/compute/instances
- Find the desired node and click on 'SSH' to open an SSH connection to the node.
Using Command Line
Method 1
First, SSH to the relevant worker node.
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 Kubelet config file:
ps -ef | grep kubelet
The output of the above command should return something similar to --config /etc/kubernetes/kubelet-config.yaml which is the location of the Kubelet config file.
Run the following command:
stat -c %a /etc/kubernetes/kubelet-config.yaml
The output of the above command is the Kubelet config file's permissions. Verify that 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.
