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:

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

blacklist can

If the command does not return any output, or the line is 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 line to the file /etc/modprobe.d/can.conf (or create atm.conf if it does not exist):

install can /bin/false
blacklist can