Vulnerability Discussion

The USBGuard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the usbguard-rules.conf file. The policy and the authorization state of USB devices can be modified during runtime using the USBGuard tool.

The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices.

Check

Note: If the system is virtual machine with no virtual or physical USB peripherals attached, this is not a finding.

Verify AlmaLinux OS 9 has USBGuard enabled with the following command:

$ systemctl status usbguard

usbguard.service - USBGuard daemon
Loaded: loaded (/usr/lib/systemd/system/usbguard.service; enabled; preset: disabled)
Active: active (running) since Thu 2024-02-08 09:42:05 UTC; 1h 24min ago

If USBGuard is not active, ask the SA to indicate how unauthorized peripherals are being blocked.

If there is no evidence that unauthorized peripherals are being blocked before establishing a connection, this is a finding.

Fix

To enable the USBGuard service run the following command:

$ systemctl enable --now usbguard