Cis K8s V1120 4.1.7

---
name: cis-k8s-v1120-4.1.7
description: "Ensure that the certificate authorities file permissions are set to 644 or more restrictive (Manual)"
category: cis-k8s
version: "1.12.0"
author: cyberstrike-official
tags: [cis, kubernetes, worker-nodes, worker-node-config, file-permissions]
cis_id: "4.1.7"
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 4.1.7

## Description

Ensure that the certificate authorities file has permissions of `644` or more restrictive.

## Rationale

The certificate authorities file controls the authorities used to validate API requests. 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 Procedure

### Step 1: Find the client-ca-file

Run the following command:

```bash
ps -ef | grep kubelet
```

Find the file specified by the `--client-ca-file` argument.

### Step 2: Verify file permissions

Run the following command:

```bash
stat -c %a <filename>
```

Verify that the permissions are `644` or more restrictive.

## Remediation

Run the following command to modify the file permissions of the `--client-ca-file`:

```bash
chmod 644 <filename>
```

## Default Value

By default no `--client-ca-file` is specified.

## References

1. https://kubernetes.io/docs/admin/authentication/#x509-client-certs

## CIS Controls

| Controls Version | Control                                                                                                                                                                                                                                          | IG 1 | IG 2 | IG 3 |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---- | ---- | ---- |
| v8               | 3.3 Configure Data Access Control Lists<br>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<br>Protect all information stored on systems with file system, network share, claims, application, or database specific access control lists.                                              | ●    | ●    | ●    |

## Profile Applicability

- Level 1 - Worker Node

## Assessment Status

Manual