Cis Ubuntu2004 V300 1 1 2 5 4

Ensure noexec option set on /var/tmp partition

Profile

Level 1 - Server, Level 1 - Workstation, Assessment: Automated

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

Command Line

• IF - a separate partition exists for /var/tmp, verify that the noexec option is set. Run the following command to verify that the noexec mount option is set. Example:

# findmnt -kn /var/tmp | grep -v noexec

Nothing should be returned

Expected Result

Nothing should be returned

Remediation

Command Line

• IF - a separate partition exists for /var/tmp. Edit the /etc/fstab file and add noexec to the fourth field (mounting options) for the /var/tmp partition. Example:

<device> /var/tmp   <fstype>   defaults,rw,nosuid,nodev,noexec,relatime   0 0

Run the following command to remount /var/tmp with the configured options:

# mount -o remount /var/tmp

Default Value

Not configured by default.

References

1. See the fstab(5) manual page for more information.
2. NIST SP 800-53 Rev. 5: AC-3, MP-2
3. NIST SP 800-53 Revision 5 :: CM-7 (2)
4. RHEL 8 STIG Vul ID: V-230522
5. RHEL 8 STIG Rule ID: SV-230522r854063

CIS Controls

v8 - 3.3 Configure Data Access Control Lists (IG 1, IG 2, IG 3) v7 - 14.6 Protect Information through Access Control Lists (IG 1, IG 2, IG 3)

MITRE ATT&CK Mappings: T1204, T1204.002 | TA0005 | M1022