RHEL 9 must disable mounting of cramfs.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-257880	RHEL-09-231195	SV-257880r1044951_rule	CCI-000381	low
Description
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.
STIG			Date
Red Hat Enterprise Linux 9 Security Technical Implementation Guide			2025-05-14

Related Frameworks

3 paths across 3 frameworks

NIST 800-531 mapping

CM-7

1.00

DISA · 2 · disa_xccdf · related
DISA · 2025-01-23 · disa_cci_list · equivalent

NIST 800-1711 mapping

3.4.6

1.00

DISA · 2 · disa_xccdf · related
DISA · 2025-01-23 · disa_cci_list · equivalent
NIST · Rev 2 (Feb 2020, errata Jan 2021) · nist_800_171_app_d · equivalent

CCI1 mapping

CCI-000381

1.00

DISA · 2 · disa_xccdf · related

Details

Check Text (C-257880r1044951_chk)

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.

Fix Text (F-61545r1044950_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