CIS Ubuntu 14.04 LTS - 1.1.9 Ensure noexec option set on /var/tmp partition

1.1.9 Ensure noexec option set on /var/tmp partition (Scored)

Profile Applicability

• Level 1 - Server
• Level 1 - Workstation

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.

Audit Procedure

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

Expected Result

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

Remediation

# 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,noexec /var/tmp

Default Value

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

References

• CIS Ubuntu Linux 14.04 LTS Benchmark v2.1.0
• CIS Controls: 2 Inventory of Authorized and Unauthorized Software

Profile

• Level 1