Canonical Ubuntu 20.04 LTS STIG Version Comparison
Canonical Ubuntu 20.04 LTS Security Technical Implementation Guide
Comparison
There are 29 differences between versions v1 r2 (Oct. 27, 2021) (the "left" version) and v1 r4 (April 27, 2022) (the "right" version).
Check UBTU-20-010461 was added to the benchmark in the "right" version.
This check's original form is available here.
Text Differences
Title
The Ubuntu operating system must disable automatic mounting of Universal Serial Bus (USB) mass storage driver.
Check Content
Verify that Ubuntu operating system disables ability to load the USB storage kernel module. # grep usb-storage /etc/modprobe.d/* | grep "/bin/true" install usb-storage /bin/true 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.
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.
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/true >> /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"