BaselineWatch
Desk
Your fleet and your work Fleetyour releases and the hardware they run onTriagewhat needs a decisionWatchlistthe products and platforms you runSaved searchesthe lists you come back to
This instance Sourceswhat is read, how often, under what termsDigestthe daily or weekly summary, and alerts
How it is drawn Appearancethe look and the colour schemeBrandingthe mark this instance wears
Owner sign-in

RHEL-09-231195 RHEL 9 must disable mounting of cramfs.

DISA STIG library V2R10
All changes in this version
first version loaded CAT III

Maps to CM-7 via CCI-000381

Title

RHEL 9 must disable mounting of cramfs.

Control

Verify that RHEL 9 disables the ability to load the cramfs kernel module with the following command: $ grep -r cramfs /etc/modprobe.conf /etc/modprobe.d/* install cramfs /bin/false blacklist cramfs If the command does not return any output or the lines are commented out, and use of cramfs is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

Discussion

It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Removing support for unneeded filesystem types reduces the local attack surface of the server. Compressed ROM/RAM file system (or cramfs) is a read-only file system designed for simplicity and space-efficiency. It is mainly used in embedded and small-footprint systems.

Related controls

CCI-000381

Fix

To configure the system to prevent the cramfs kernel module from being loaded, add the following lines to the file /etc/modprobe.d/blacklist.conf (or create blacklist.conf if it does not exist): install cramfs /bin/false blacklist cramfs