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cis-ubuntu1604-v200-1-1-8

DevOps & Security
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Ensure nosuid option set on /dev/shm partition

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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-v200-1-1-8/SKILL.md

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Ensure nosuid option set on /dev/shm partition

Description

The nosuid mount option specifies that the filesystem cannot contain setuid files.

Rationale

Setting this option on a file system prevents users from introducing privileged programs onto the system and allowing non-root users to execute them.

Impact

None noted.

Audit Procedure

Command Line

# Run the following command and verify that nothing is returned:
findnmt -n /dev/shm | grep -v nosuid

Expected Result

No output should be returned.

Remediation

Command Line

# Edit the /etc/fstab file and add nosuid to the fourth field (mounting options) for the /dev/shm partition.
# See the fstab(5) manual page for more information.
# Run the following command to remount /dev/shm:
mount -o remount,nosuid,nodev,noexec /dev/shm

Default Value

Not set 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