Ensure mounting of squashfs filesystems is disabled - lsmod

Information

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.

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

See Also

https://www.cisco.com/c/en/us/td/docs/security/firepower/623/configuration/guide/fpmc-config-guide-v623.html