Profile Applicability:
 • Level 1

Description:
 The nodev mount option prevents device files from being interpreted on the mounted filesystem. Applying this option to /var/log/audit helps prevent the creation and use of device files that could be exploited for privilege escalation or unauthorized access.

Rationale:
 Setting the nodev option on /var/log/audit reduces the risk of device file abuse, which can lead to compromise of audit logs or unauthorized system access.

Impact:
 Pros:

  • Prevents device file exploitation on /var/log/audit.

  • Enhances overall system security posture.

Cons:

  • May interfere with legitimate device file operations if any exist in /var/log/audit (rare).

Default Value:
 By default, the nodev option is often not set on /var/log/audit unless explicitly configured.

Pre-requisites:

  • Root or sudo privileges to modify /etc/fstab and remount filesystems.

  • /var/log/audit must be mounted as a separate partition.

Remediation:

Test Plan:

Using Linux command line:

  1. Check current mount options for /var/log/audit:

     mount | grep /var/log/audit

  2. Verify if nodev is present in /etc/fstab for /var/log/audit:

     grep /var/log/audit /etc/fstab
    Expected output: Mount options for /var/log/audit include nodev.

Implementation Plan:

Using Linux command line:

  1. Edit /etc/fstab to add nodev to the mount options for /var/log/audit. Example:
    /dev/<partition>  /var/log/audit  ext4  defaults,nodev,nosuid,noexec  0  0

  2. Remount /var/log/audit with the new options without reboot:

     mount -o remount,nodev /var/log/audit

  3. Verify mount options:

     mount | grep /var/log/audit

Backout Plan:

Using Linux command line:

  1. Remove nodev from /var/log/audit mount options in /etc/fstab.

  2. Remount /var/log/audit without nodev:

     mount -o remount /var/log/audit


  3. Verify mount options:

     mount | grep /var/log/audit

References: