OL 8 must not have the Controller Area Network (CAN) kernel module installed if not required for operational support.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-248830	OL08-00-040022	SV-248830r780056_rule		Medium

Description
The CAN protocol is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other's applications without a host computer. Disabling CAN protects the system against exploitation of any flaws in its implementation.

STIG	Date
Oracle Linux 8 Security Technical Implementation Guide	2022-09-07

Details

Check Text ( C-52264r780054_chk )
Verify the operating system disables the ability to load the "can" kernel module. $ sudo grep -r can /etc/modprobe.d/* \| grep -i "/bin/false" \| grep -v "^#" install can /bin/true 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. Verify the operating system disables the ability to use CAN with the following command: $ sudo grep can /etc/modprobe.d/* \| grep -i "blacklist" \| grep -v "^#" blacklist can If the command does not return any output or the output is not "blacklist can", and use of CAN is not documented with the ISSO as an operational requirement, this is a finding.

Check Text ( C-52264r780054_chk )

Verify the operating system disables the ability to load the "can" kernel module.

$ sudo grep -r can /etc/modprobe.d/* | grep -i "/bin/false" | grep -v "^#"

install can /bin/true

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.

Verify the operating system disables the ability to use CAN with the following command:

$ sudo grep can /etc/modprobe.d/* | grep -i "blacklist" | grep -v "^#"

blacklist can

If the command does not return any output or the output is not "blacklist can", and use of CAN is not documented with the ISSO as an operational requirement, this is a finding.

Fix Text (F-52218r780055_fix)
Configure OL 8 to disable the ability to use the "can" kernel module. Create a file under "/etc/modprobe.d" with the following command: $ sudo touch /etc/modprobe.d/can.conf Add the following line to the created file: install can /bin/true Configure OL 8 to disable the ability to use the can kernel module. $ sudo vi /etc/modprobe.d/blacklist.conf Add or update the line: blacklist can