cis-ubuntu1604-v200-1-1-1-6

DevOps & Security

Ensure mounting of udf 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-v200-1-1-1-6/SKILL.md

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Ensure mounting of udf filesystems is disabled

Description

The udf filesystem type is the universal disk format used to implement ISO/IEC 13346 and ECMA-167 specifications. This is an open vendor filesystem type for data storage on a broad range of media. This filesystem type is necessary to support writing DVDs and newer optical disc formats.

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 udf | grep -E '(udf|install)'
# lsmod | grep udf

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/udf.conf
# and add the following line:
install udf /bin/true

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

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