STIGUI
V-271701CAT II — Medium severitySV-271701r1091815_rule

OL 9 must block unauthorized peripherals before establishing a connection.

Rule version OL09-00-002331 · STIG v1 · 2026-08-21

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

Verify that OL 9 USBGuard has a policy configured with the following command:

$ usbguard list-rules allow id 1d6b:0001 serial

If the command does not return results or an error is returned, 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

Configure the operating system to enable the blocking of unauthorized peripherals with the following command:

Note: This command must be run from a root shell and will create an allow list for any USB devices currently connect to the system.

# usbguard generate-policy --no-hash > /etc/usbguard/rules.conf

Note: Enabling and starting USBGuard without properly configuring it for an individual system will immediately prevent any access over a USB device such as a keyboard or mouse.

Identifiers

Group ID
V-271701
Group title
SRG-OS-000378-GPOS-00163
Rule ID
SV-271701r1091815_rule
Check ID
C-75751r1091813_chk
Fix ID
F-75658r1091814_fix