cyberstrikeus 1.1.1.1 Ensure mounting of cramfs filesystems is disabled (Scored)
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Description
The cramfs filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems. A cramfs image can be used without having to first decompress the image.
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 Procedure
modprobe -n -v cramfs
# Expected output: install /bin/true
lsmod | grep cramfs
# Expected output: <No output>
Expected Result
modprobe -n -v cramfs should return install /bin/true and lsmod | grep cramfs should return no output.
Remediation
# Edit or create the file /etc/modprobe.d/CIS.conf and add the following line:
echo "install cramfs /bin/true" >> /etc/modprobe.d/CIS.conf
# Unload the cramfs module:
rmmod cramfs
Default Value
By default, cramfs filesystem mounting is allowed.
References
- CIS Ubuntu Linux 14.04 LTS Benchmark v2.1.0
- CIS Controls: 13 Data Protection
Profile
- Level 1