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CIS Ubuntu 14.04 LTS - 1.1.16 Ensure noexec option set on /run/shm partition

DevOps & Security
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Ensure noexec option is set on /run/shm partition to prevent executable binaries

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Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Operating_Systems/Ubuntu/CIS_Ubuntu_Linux_14.04_LTS_Benchmark_v2.1.0/cis-ubuntu1404-v210-1-1-16/SKILL.md

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1.1.16 Ensure noexec option set on /run/shm partition (Scored)

Profile Applicability

  • Level 1 - Server
  • Level 1 - Workstation

Description

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

Rationale

Setting this option on a file system prevents users from executing programs from shared memory. This deters users from introducing potentially malicious software on the system.

Audit Procedure

mount | grep /run/shm
# Verify that the noexec option is set on /run/shm
# Expected output: tmpfs on /run/shm type tmpfs (rw,nosuid,nodev,noexec,relatime)

Expected Result

The output should show the noexec option is set for the /run/shm partition.

Remediation

# Edit the /etc/fstab file and add noexec to the fourth field (mounting options)
# for the /run/shm partition. See the fstab(5) manual page for more information.

# Run the following command to remount /run/shm:
mount -o remount,noexec /run/shm

Default Value

By default, the noexec option is not set on /run/shm.

References

  • CIS Ubuntu Linux 14.04 LTS Benchmark v2.1.0

Profile

  • Level 1