Run the following script to disable the cramfs module: If the module is available in the running kernel: - Create a file with install usb-storage /bin/false in the /etc/modprobe.d/ directory - Create a file with blacklist usb-storage in the /etc/modprobe.d/ directory - Unload usb-storage from the kernel If available in ANY installed kernel: - Create a file with blacklist usb-storage in the /etc/modprobe.d/ directory If the kernel module is not available on the system: - No remediation is necessary #!/usr/bin/env bash { l_mname="usb-storage" # set module name l_mtype="drivers" # set module type l_mpath="/lib/modules/**/kernel/$l_mtype" l_mpname="$(tr '-' '_' <<< "$l_mname")" l_mndir="$(tr '-' '/' <<< "$l_mname")" module_loadable_fix() { # If the module is currently loadable, add "install {MODULE_NAME} /bin/false" to a file in "/etc/modprobe.d" l_loadable="$(modprobe -n -v "$l_mname")" [ "$(wc -l <<< "$l_loadable")" -gt "1" ] && l_loadable="$(grep -P -- "(^\h*install|\b$l_mname)\b" <<< "$l_loadable")" if ! grep -Pq -- '^\h*install \/bin\/(true|false)' <<< "$l_loadable"; then echo -e "\n - setting module: \"$l_mname\" to be not loadable" echo -e "install $l_mname /bin/false" >> /etc/modprobe.d/"$l_mpname".conf fi } module_loaded_fix() { # If the module is currently loaded, unload the module if lsmod | grep "$l_mname" > /dev/null 2>&1; then echo -e "\n - unloading module \"$l_mname\"" modprobe -r "$l_mname" fi } module_deny_fix() { # If the module isn't deny listed, denylist the module if ! modprobe --showconfig | grep -Pq -- "^\h*blacklist\h+$l_mpname\b"; then echo -e "\n - deny listing \"$l_mname\"" echo -e "blacklist $l_mname" >> /etc/modprobe.d/"$l_mpname".conf fi } # Check if the module exists on the system for l_mdir in $l_mpath; do if [ -d "$l_mdir/$l_mndir" ] && [ -n "$(ls -A $l_mdir/$l_mndir)" ]; then echo -e "\n - module: \"$l_mname\" exists in \"$l_mdir\"\n - checking if disabled..." module_deny_fix if [ "$l_mdir" = "/lib/modules/$(uname -r)/kernel/$l_mtype" ]; then module_loadable_fix module_loaded_fix fi else echo -e "\n - module: \"$l_mname\" doesn't exist in \"$l_mdir\"\n" fi done echo -e "\n - remediation of module: \"$l_mname\" complete\n" } Impact: Disabling the usb-storage module will disable any usage of USB storage devices. If requirements and local site policy allow the use of such devices, other solutions should be configured accordingly instead. One example of a commonly used solution is USBGuard.

Name	Audit Name	Plugin	Category
1.1.10 Disable USB Storage	CIS Ubuntu Linux 18.04 LTS v2.2.0 L1 Server	Unix	MEDIA PROTECTION, SYSTEM AND INFORMATION INTEGRITY
1.1.10 Disable USB Storage	CIS Ubuntu Linux 18.04 LTS v2.2.0 L2 Workstation	Unix	MEDIA PROTECTION, SYSTEM AND INFORMATION INTEGRITY

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