Cis K8s V200 4.1.9

---
name: cis-k8s-v200-4.1.9
description: "If the kubelet config.yaml configuration file is being used validate permissions set to 600 or more restrictive (Automated)"
category: cis-k8s
version: "2.0.0"
author: cyberstrike-official
tags: [cis, kubernetes, worker-node, config-files, file-permissions, kubelet-config]
cis_id: "4.1.9"
cis_benchmark: "CIS Kubernetes Benchmark v2.0.0"
tech_stack: [kubernetes]
cwe_ids: []
chains_with: []
prerequisites: []
severity_boost: {}
---

# 4.1.9 If the kubelet config.yaml configuration file is being used validate permissions set to 600 or more restrictive (Automated)

## Profile Applicability

- Level 1 - Worker Node

## Description

Ensure that if the kubelet refers to a configuration file with the `--config` argument, that file has permissions of 600 or more restrictive.

## 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 writable by only the administrators on the system.

## 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:

```bash
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,

```bash
stat -c %a /var/lib/kubelet/config.yaml
```

Verify that the permissions are `600` or more restrictive.

## Remediation

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

```bash
chmod 600 /var/lib/kubelet/config.yaml
```

## Default Value

By default, the /var/lib/kubelet/config.yaml file as set up by `kubeadm` has permissions of 600.

## References

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

## CIS Controls

| Controls Version | Control                                                                                                                                                                                                                                                                                                                                                                                                | IG 1 | IG 2 | IG 3 |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---- | ---- | ---- |
| v8               | 3.3 Configure Data Access Control Lists - Configure data access control lists based on a user's need to know. Apply data access control lists, also known as access permissions, to local and remote file systems, databases, and applications.                                                                                                                                                        | \*   | \*   | \*   |
| v7               | 14.6 Protect Information through Access Control Lists - Protect all information stored on systems with file system, network share, claims, application, or database specific access control lists. These controls will enforce the principle that only authorized individuals should have access to the information based on their need to access the information as a part of their responsibilities. | \*   | \*   | \*   |