Details

The `squashfs` filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems (similar to `cramfs` ). A `squashfs` image can be used without having to first decompress the image.

Removing support for unneeded filesystem types reduces the local attack surface of the system. If this filesystem type is not needed, disable it.

Solution

Edit or create the file `/etc/modprobe.d/CIS.conf` and add the following line:
“`
install squashfs /bin/true
“`
Run the following command to unload the `squashfs` module:
“`
# rmmod squashfs
“`

Supportive Information

The following resource is also helpful.

• https://workbench.cisecurity.org/files/1863

This security hardening control applies to the following category of controls within NIST 800-53: Configuration Management.This control applies to the following type of system Unix.

References

• 800-53|CM-7b.
• CSCv6|13

Source

• Tenable.com/audits