Vulnerability Discussion
USB mass storage permits easy introduction of unknown devices, thereby facilitating malicious activity.
Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227
Check
Verify that RHEL 9 disables the ability to load the USB Storage kernel module with the following command:
$ sudo grep -r usb-storage /etc/modprobe.conf /etc/modprobe.d/*
blacklist usb-storage
If the command does not return any output, or the line is commented out, and use of USB Storage 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 usb-storage kernel module from being loaded, add the following line to the file /etc/modprobe.d/usb-storage.conf (or create usb-storage.conf if it does not exist):
install usb-storage /bin/false
blacklist usb-storage