Cis Docker 5.30
DevOps & Securitycis-docker-5.30Cis Docker 5.30 is an Agent Skill for devops & security published in the CyberStrikeus/CyberStrike repository on GitHub: a SKILL.md instruction file an AI agent can load to do this task.
Ensure that Docker's default bridge docker0 is not used
How to use this skill
Bring this guide into your coding agent with a prompt tailored to the tool you use.
- Open your project in Codex.
- Copy and paste the prompt below.
- Review files and risks before approving any action.
Inspect the Agent Skill at https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Server_Software/Docker/CIS_Docker_Benchmark_v1.8.0/cis-docker-5.30/SKILL.md and all supporting files. Report provenance, permissions, scripts, dependencies, and security risks. Propose an exact installation into .agents/skills/cis-docker-5-30, but wait for my approval before writing files or running scripts.
Copying this prompt does not install or run the skill. Review third-party files before use.
5.30 Ensure that Docker's default bridge "docker0" is not used (Manual)
Profile Applicability
- Level 2 - Docker - Linux
Description
You should not use Docker's default bridge docker0. Instead you should use Docker's user-defined networks for container networking.
Rationale
Docker connects virtual interfaces created in bridge mode to a common bridge called docker0. This default networking model is vulnerable to ARP spoofing and MAC flooding attacks as there is no filtering applied to it.
Impact
User-defined networks need to be configured and managed in line with organizational security policy.
Audit Procedure
You should run the command below, and verify that containers are on a user-defined network and not the default docker0 bridge.
docker network ls --quiet | xargs docker network inspect --format '{{ .Name }}: {{ .Options }}'
Remediation
You should follow the Docker documentation and set up a user-defined network. All the containers should be run in this network.
Default Value
By default, Docker runs containers within the default docker0 bridge.
References
CIS Controls
| Controls Version | Control | IG 1 | IG 2 | IG 3 |
|---|---|---|---|---|
| v8 | 4.8 Uninstall or Disable Unnecessary Services on Enterprise Assets and SoftwareUninstall or disable unnecessary services on enterprise assets and software, such as an unused file sharing service, web application module, or service function. | ● | ● | |
| v6 | 9 Limitation and Control of Network Ports, Protocols, and ServicesLimitation and Control of Network Ports, Protocols, and Services |