Details

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.

Solution

Edit or create a file in the /etc/modprobe.d/ directory ending in .conf
Example: vim /etc/modprobe.d/cramfs.conf
and add the following line:

install cramfs /bin/true

Run the following command to unload the cramfs module:

# rmmod cramfs

Supportive Information

The following resource is also helpful.

• https://workbench.cisecurity.org/files/3490

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

References

• 800-53|CM-1
• 800-53|CM-2
• 800-53|CM-6
• 800-53|CM-7
• 800-53|IA-5
• CSCv7|5.1

Source

• Tenable.com/audits