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1.1.2.4.3 Ensure nosuid option set on /var partition

Information

The nosuid mount option specifies that the filesystem cannot contain setuid files.

Since the /var filesystem is only intended for variable files such as logs, set this option to ensure that users cannot create setuid files in /var.

Solution

- IF - a separate partition exists for /var.

Edit the /etc/fstab file and add nosuid to the fourth field (mounting options) for the /var partition.

Example:

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

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

# mount -o remount /var

Impact:

Setting the nosuid option prevents setuid and setgid bits from taking effect on the /var filesystem, which is not expected to contain privileged executables; this typically has no operational impact.

See Also

https://workbench.cisecurity.org/benchmarks/27892

Item Details

Category: ACCESS CONTROL, MEDIA PROTECTION

References: 800-53|AC-3, 800-53|AC-5, 800-53|AC-6, 800-53|MP-2, CSCv7|14.6

Plugin: Unix

Control ID: 0bd671197007318c962b9d399b54f9982174eb4168b71619f26ccbc60d063b29