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CIS Ubuntu 14.04 LTS - 1.1.3 Ensure nodev option set on /tmp partition

DevOps & Security
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Ensure nodev option is set on /tmp partition to prevent special device access

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1.1.3 Ensure nodev option set on /tmp partition (Scored)

Profile Applicability

  • Level 1 - Server
  • Level 1 - Workstation

Description

The nodev mount option specifies that the filesystem cannot contain special devices.

Rationale

Since the /tmp filesystem is not intended to support devices, set this option to ensure that users cannot attempt to create block or character special devices in /tmp.

Audit Procedure

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

Expected Result

The output should show the nodev option is set for the /tmp partition.

Remediation

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

# Run the following command to remount /tmp:
mount -o remount,nodev /tmp

Default Value

By default, the nodev option is not set on /tmp.

References

  • CIS Ubuntu Linux 14.04 LTS Benchmark v2.1.0

Notes

systemd includes the tmp.mount service which should be used instead of configuring /etc/fstab. Mounting options are configured in the Options setting in /etc/systemd/system/tmp.mount.

Profile

  • Level 1