Cis Docker 2.12
DevOps & Securitycis-docker-2.12Cis Docker 2.12 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 base device size is not changed until needed
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-2.12/SKILL.md and all supporting files. Report provenance, permissions, scripts, dependencies, and security risks. Propose an exact installation into .agents/skills/cis-docker-2-12, but wait for my approval before writing files or running scripts.
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Ensure base device size is not changed until needed (Manual)
Profile Applicability
• Level 2 - Docker - Linux
Description
Under certain circumstances, you might need containers larger than 10G. Where this applies you should carefully choose the base device size.
Rationale
The base device size can be increased on daemon restart. Increasing the base device size allows all future images and containers to be of the new base device size. A user can use this option to expand the base device size however shrinking is not permitted. This value affects the system wide "base" empty filesystem that may already be initialized and inherited by pulled images.
Although the file system does not allocate the increased size as long as it is empty, more space will be allocated for extra images. This may cause a denial of service condition if the allocated partition becomes full.
Impact
None.
Audit Procedure
To confirm this setting the dockerd start-up options and any settings in /etc/docker/daemon.json should be reviewed.
To review the dockerd startup options, use:
grep "--storage-opt dm.basesize" /etc/docker/daemon.json
Execute the above command and it should not show any --storage-opt dm.basesize parameters.
The contents of /etc/docker/daemon.json should also be reviewed
Remediation
Do not set --storage-opt dm.basesize until needed.
Default Value
The default base device size is 10G.
References
CIS Controls
Controls Version: v8
Control: 16.7 Use Standard Hardening Configuration Templates for Application Infrastructure
Use standard, industry-recommended hardening configuration templates for application infrastructure components. This includes underlying servers, databases, and web servers, and applies to cloud containers, Platform as a Service (PaaS) components, and SaaS components. Do not allow in-house developed software to weaken configuration hardening.
IG 1: IG 2: ● IG 3: ●
Controls Version: v7
Control: 18 Application Software Security
Application Software Security