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cis-ubuntu1604-v200-1-1-14

DevOps & Security
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Ensure /var/tmp partition includes the noexec option

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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-v200-1-1-14/SKILL.md

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Ensure /var/tmp partition includes the noexec option

Description

The noexec mount option specifies that the filesystem cannot contain executable binaries.

Rationale

Since the /var/tmp filesystem is only intended for temporary file storage, set this option to ensure that users cannot run executable binaries from /var/tmp.

Impact

None noted.

Audit Procedure

Command Line

# If a /var/tmp partition exists, verify that the noexec option is set.
# Run the following command and verify that nothing is returned:
findmnt -n /var/tmp | grep -v noexec

Expected Result

No output should be returned.

Remediation

Command Line

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

Default Value

Not set by default.

References

  • CIS Controls Version 7 - 2.6 Address unapproved software: Ensure that unauthorized software is either removed or the inventory is updated in a timely manner.

Profile

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