Ubuntu OS must disable automatic mounting of Universal Serial Bus (USB) mass storage driver.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-275631	SRG-OS-000378-GPOS-00163	RIIM-OS-291010	SV-275631r1147943_rule	2025-10-02	1

Description
Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Peripherals include, but are not limited to, such devices as flash drives, external storage, and printers. Satisfies: SRG-OS-000378-GPOS-00163, SRG-OS-000690-GPOS-00140

ℹ️ Check
Verify Ubuntu OS disables ability to load the USB storage kernel module by using the following command: $ grep usb-storage /etc/modprobe.d/* \| grep "/bin/false" /etc/modprobe.d/stig.conf:install usb-storage /bin/false If the command does not return any output, or the line is commented out, this is a finding. Verify Ubuntu OS disables the ability to use USB mass storage device. $ grep usb-storage /etc/modprobe.d/* \| grep -i "blacklist" /etc/modprobe.d/stig.conf:blacklist usb-storage If the command does not return any output, or the line is commented out, this is a finding.

ℹ️ Check

Verify Ubuntu OS disables ability to load the USB storage kernel module by using the following command: $ grep usb-storage /etc/modprobe.d/* | grep "/bin/false" /etc/modprobe.d/stig.conf:install usb-storage /bin/false If the command does not return any output, or the line is commented out, this is a finding. Verify Ubuntu OS disables the ability to use USB mass storage device. $ grep usb-storage /etc/modprobe.d/* | grep -i "blacklist" /etc/modprobe.d/stig.conf:blacklist usb-storage If the command does not return any output, or the line is commented out, this is a finding.

✔️ Fix
Configure Ubuntu OS to disable using the USB storage kernel module. Create and/or append a custom file under "/etc/modprobe.d/" to contain the following: $ sudo su -c "echo install usb-storage /bin/false >> /etc/modprobe.d/stig.conf" Configure Ubuntu OS to disable the ability to use USB mass storage devices. $ sudo su -c "echo blacklist usb-storage >> /etc/modprobe.d/stig.conf"