cis-ubuntu1204-v110-2-4

DevOps & Security

Set noexec option for /tmp Partition

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2.4 Set noexec option for /tmp Partition (Scored)

Profile Applicability

Level 1

Description

The noexec mount option specifies that the filesystem cannot contain executable binaries.

Rationale

Since the /tmp filesystem is only intended for temporary file storage, set this option to ensure that users cannot run executable binaries from /tmp.

Audit Procedure

Using Command Line

grep /tmp /etc/fstab | grep noexec
mount | grep /tmp | grep noexec

Expected Result

Both commands should return output showing noexec is set. If either command emits no output then the system is not configured as recommended.

Remediation

Using Command Line

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

mount -o remount,noexec /tmp

Default Value

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

References

CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

Profile

Level 1 - Scored