1.1.1.8 Ensure mounting of FAT filesystems is disabled (Scored)
Profile Applicability
Level 1 - Server Level 2 - Workstation
Description
The FAT
filesystem format is primarily used on older windows systems and portable USB drives or flash modules. It comes in three types FAT12
, FAT16
, and FAT32
all of which are supported by the vfat
kernel module.
Rationale
Removing support for unneeded filesystem types reduces the local attack surface of the server. If this filesystem type is not needed, disable it.
Audit
Run the following commands and verify the output is as indicated:
# modprobe -n -v vfat install /bin/true # lsmod | grep vfat <No output>
Remediation
Edit or create the file /etc/modprobe.d/CIS.conf
and add the following line:
install vfat /bin/true
Impact
FAT filesystems are often used on portable USB sticks and other flash media are commonly used to transfer files between workstations, removing VFAT support may prevent the ability to transfer files in this way.