Profile Applicability:
 • Level 1

Description:
 The noexec mount option prevents execution of binaries on the mounted filesystem. Applying this option to /var/log mitigates the risk of executing unauthorized or malicious binaries from the log directory.

Rationale:
 Setting the noexec option on /var/log reduces the risk that attackers can execute malicious code from this partition, strengthening system security.

Impact:
 Pros:

  • Helps prevent execution of unauthorized binaries or scripts in /var/log.

  • Enhances overall security posture.

Cons:

  • Some applications or services might require execution privileges in /var/log, which could be impacted.

Default Value:
 The noexec option is typically not set on /var/log unless explicitly configured.

Pre-requisites:

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

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

Remediation:

Test Plan:

Using Linux command line:

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

     mount | grep /var/log

  2. Verify if noexec is included in /etc/fstab for /var/log:

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


Implementation Plan:

Using Linux command line:

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


  2. Remount /var/log with new options:

     mount -o remount,noexec /var/log

  3. Verify mount options:

     mount | grep /var/log

Backout Plan:

Using Linux command line:

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

  2. Remount /var/log without noexec:

     mount -o remount /var/log

  3. Verify mount options:

     mount | grep /var/log

References: