# Cis Docker V160 2.5

> Ensure insecure registries are not used

- Skill: `cyberstrikeus/cis-docker-v160-2-5` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-docker-v160-2-5`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-docker-v160-2-5/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-docker-v160-2-5

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# Ensure insecure registries are not used

**Profile Applicability:** Level 1 - Docker - Linux

**Assessment Status:** Manual

## Description

Docker considers a private registry either secure or insecure. By default, registries are considered secure.

## Rationale

A secure registry uses TLS. A copy of registry's CA certificate is placed on the Docker host at `/etc/docker/certs.d/<registry-name>/` directory. An insecure registry is one which does not have a valid registry certificate, or one not using TLS. Insecure registries should not be used as they present a risk of traffic interception and modification.

Additionally, once a registry has been marked as insecure commands such as `docker pull`, `docker push`, and `docker search` will not result in an error message and users may indefinitely be working with this type of insecure registry without ever being notified of the risk of potential compromise.

## Impact

None.

## Audit Procedure

You should execute the command below to find out if any insecure registries are in use:

```bash
docker info --format 'Insecure Registries:
{{.RegistryConfig.InsecureRegistryCIDRs}}'
```

## Remediation

You should ensure that no insecure registries are in use.

## Default Value

By default, Docker assumes all, but local, registries are secure.

## References

1. https://docs.docker.com/registry/insecure/

## CIS Controls

| Controls Version | Control                                                                                                                                                                                                      | IG 1 | IG 2 | IG 3 |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---- | ---- | ---- |
| v8               | 2.5 Allowlist Authorized Software<br>Use technical controls, such as application allowlisting, to ensure that only authorized software can execute or be accessed. Reassess bi-annually, or more frequently. |      | ●    | ●    |
| v7               | 14.4 Encrypt All Sensitive Information in Transit<br>Encrypt all sensitive information in transit.                                                                                                           |      | ●    | ●    |

## Profile/Assessment Status

**Profile:** Level 1 - Docker - Linux
**Assessment Status:** Manual