cis-ubuntu1604-v200-1-1-1-3

DevOps & Security

Ensure mounting of jffs2 filesystems is disabled

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Prompt to paste

I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Operating_Systems/Ubuntu/CIS_Ubuntu_Linux_16.04_LTS_Benchmark_v2.0.0/cis-ubuntu1604-v200-1-1-1-3/SKILL.md

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First, summarize what it does, its dependencies, license status if identifiable, and any risks. Show the exact files you propose to add under .agents/skills/cis-ubuntu1604-v200-1-1-1-3/. Do not write files or run scripts until I approve.

After I approve, install the complete skill folder, including required referenced files, into that project location. Verify it is discoverable, then tell me its actual invocation name and how to use it. Do not claim it is installed until you have verified it.

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Ensure mounting of jffs2 filesystems is disabled

Description

The jffs2 (journaling flash filesystem 2) filesystem type is a log-structured filesystem used in flash memory devices.

Rationale

Removing support for unneeded filesystem types reduces the local attack surface of the system. If this filesystem type is not needed, disable it.

Impact

None noted.

Audit Procedure

Command Line

# modprobe -n -v jffs2 | grep -E '(jffs2|install)'
# lsmod | grep jffs2

Expected Result

install /bin/true

The lsmod command should return no output.

Remediation

Command Line

# Edit or create a file in the /etc/modprobe.d/ directory ending in .conf
# Example: vi /etc/modprobe.d/jffs2.conf
# and add the following line:
install jffs2 /bin/true

# Run the following command to unload the jffs2 module:
rmmod jffs2

Default Value

Not disabled by default.

References

CIS Controls Version 7 - 5.1 Establish Secure Configurations: Maintain documented, standard security configuration standards for all authorized operating systems and software.

Profile

Level 1 - Server / Level 1 - Workstation, Assessment: Automated