RHEL 9 must be configured to disable the Controller Area Network kernel module.

STIG ID: RHEL-09-213050  |  SRG: SRG-OS-000095-GPOS-00049 |  Severity: medium |  CCI: CCI-000381 |  Vulnerability Id: V-257805

Vulnerability Discussion

Disabling Controller Area Network (CAN) protects the system against exploitation of any flaws in its implementation.

Check

Verify that RHEL 9 disables the ability to load the CAN kernel module with the following command:

$ grep -r can /etc/modprobe.conf /etc/modprobe.d/*

install can /bin/false
blacklist can

If the command does not return any output, or the lines are commented out, and use of CAN is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

Fix

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

install can /bin/false
blacklist can