# Cis Docker 3.18

> Ensure that daemon.json file permissions are set to 644 or more restrictive

- Skill: `cyberstrikeus/cis-docker-3-18` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-docker-3-18`
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- Category: DevOps & Infra
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-docker-3-18

---


# Ensure that daemon.json file permissions are set to 644 or more restrictive (Manual)

## Profile Applicability

- Level 2 - Docker - Linux

## Description

You should verify that if the `daemon.json` is present its file permissions are correctly set to `644` or more restrictively.

## Rationale

The `daemon.json` file contains sensitive parameters that may alter the behavior of the docker daemon. Therefore it should be writeable only by `root` to ensure it is not modified by less privileged users.

## Impact

None.

## Audit Procedure

You should execute the command below to verify that the file permissions are correctly set to `644` or more restrictively:

```bash
stat -c %a /etc/docker/daemon.json
```

If the command returns the result below, the file is not present and this check does not apply:

```
stat: cannot stat '/etc/docker/daemon.json': No such file or directory
```

## Remediation

If the file is present, you should execute the command below:

```bash
chmod 644 /etc/docker/daemon.json
```

This sets the file permissions for this file to `644`.

## Default Value

This file may not be present on the system, and in that case, this recommendation is not applicable.

## References

1. https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-configuration-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. | ●    | ●    | ●    |