Vulnerability Discussion

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.

Check

Note: The "install" and "blacklist" methods are utilized together to fully disable automatic mounting of the USB mass storage driver.

Verify the Ubuntu operating system disables the ability to load the USB storage kernel module:
$ grep usb-storage /etc/modprobe.d/* | grep "/bin/false"

install usb-storage /bin/false

If the command does not return any output, or the line is commented out, this is a finding.

Verify the operating system disables the ability to use USB mass storage device:
$ grep usb-storage /etc/modprobe.d/* | grep -i "blacklist"

blacklist usb-storage

If the command does not return any output, or the line is commented out, this is a finding.

Fix

Configure the Ubuntu operating system to disable using the USB storage kernel module.

Create a file under "/etc/modprobe.d" to contain the following:
$ sudo su -c "echo install usb-storage /bin/false >> /etc/modprobe.d/DISASTIG.conf"

Configure the operating system to disable the ability to use USB mass storage devices:
$ sudo su -c "echo blacklist usb-storage >> /etc/modprobe.d/DISASTIG.conf"