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|
#!/bin/sh
#################################################################################
#
# Lynis
# ------------------
#
# Website : https://cisofy.com
# Blog : https://linux-audit.com/
# GitHub : https://github.com/CISOfy/lynis
#
# Lynis comes with ABSOLUTELY NO WARRANTY. This is free software, and you are
# welcome to redistribute it under the terms of the GNU General Public License.
# See LICENSE file for usage of this software.
#
#################################################################################
#
# USB Devices
#
#################################################################################
#
InsertSection "${SECTION_USB_DEVICES}"
#
#################################################################################
#
USBGUARD_FOUND=0
USBGUARD_CONFIG=""
USBGUARD_RULES=""
USBGUARD_RESTORE_POLICY=""
USBGUARD_CONTROLLER_POLICY=""
USBGUARD_DEVICE_POLICY=""
USBGUARD_INSERTED_POLICY=""
USBGUARD_DEFAULT_POLICY=""
USBGUARD_RULES_ALLOW=0
USBGUARD_RULES_BLOCK=0
USBGUARD_RULES_REJECT=0
#
#################################################################################
#
# Test to determine if USBGuard is installed. If it is, we will limit
# suggestions from other tests.
if [ -n "${USBGUARDBINARY}" ]; then
USBGUARD_FOUND=1
fi
#
#################################################################################
#
# Test : USB-1000 (was STRG-1840)
# Description : Check for disabled USB storage
Register --test-no USB-1000 --os Linux --weight L --network NO --category security --description "Check if USB storage is disabled"
if [ ${SKIPTEST} -eq 0 ]; then
FOUND=0
LogText "Test: Checking USB storage driver in directory /etc/modprobe.d and configuration file /etc/modprobe.conf"
if [ -d /etc/modprobe.d ]; then
FIND=$(${LSBINARY} ${ROOTDIR}etc/modprobe.d/* 2> /dev/null)
if [ -n "${FIND}" ]; then
FIND=$(${GREPBINARY} -E -r "install usb[-_]storage /bin/(false|true)" ${ROOTDIR}etc/modprobe.d/* | ${GREPBINARY} -v "#")
FIND2=$(${GREPBINARY} -E -r "^blacklist usb[-_]storage" ${ROOTDIR}etc/modprobe.d/*)
if [ -n "${FIND}" -o -n "${FIND2}" ]; then
FOUND=1
LogText "Result: found usb-storage driver in disabled state (blacklisted)"
fi
else
LogText "Result: uncommon situation. Found /etc/modprobe.d directory, but no files in it."
fi
fi
if [ -f ${ROOTDIR}etc/modprobe.conf ]; then
FIND=$(${GREPBINARY} -E "install usb[-_]storage /bin/(false|true)" ${ROOTDIR}etc/modprobe.conf | ${GREPBINARY} "usb-storage" | ${GREPBINARY} -v "#")
if [ -n "${FIND}" ]; then
FOUND=1
LogText "Result: found usb-storage driver in disabled state"
fi
fi
if [ ${FOUND} -eq 0 ]; then
LogText "Result: usb-storage driver is not explicitly disabled"
Display --indent 2 --text "- Checking usb-storage driver (modprobe config)" --result "${STATUS_NOT_DISABLED}" --color WHITE
if [ "${USBGUARD_FOUND}" -eq "0" ]; then
ReportSuggestion "${TEST_NO}" "Disable drivers like USB storage when not used, to prevent unauthorized storage or data theft"
fi
AddHP 2 3
else
LogText "Result: usb-storage driver is disabled"
Display --indent 2 --text "- Checking usb-storage driver (modprobe config)" --result "${STATUS_DISABLED}" --color GREEN
AddHP 3 3
fi
fi
#
#################################################################################
#
# Test : USB-2000 (was STRG-1842)
# Description : Check USB authorizations
Register --test-no USB-2000 --os Linux --weight L --network NO --category security --description "Check USB authorizations"
if [ ${SKIPTEST} -eq 0 ]; then
FOUND=0
USBDEVICESPATH="${ROOTDIR}sys/bus/usb/devices"
LogText "Test: checking presence of USB devices path (${USBDEVICESPATH})"
if [ -d "${USBDEVICESPATH}" ]; then
LogText "Test: Checking USB devices authorization to connect to the system"
for device in $(find ${USBDEVICESPATH} -name "usb*" -type l -print); do
if [ -e "${device}/authorized" -o -e "${device}/authorized_default" ]; then
if [ "$(cat "${device}/authorized_default")" = "1" ]; then
FOUND=1
LogText "Test: ${device} is authorized by default (authorized_default=1)"
Report "usb_authorized_default_device[]=${device}"
fi
if [ "$(cat "${device}/authorized")" = "1" ]; then
FOUND=1
LogText "Test: ${device} is authorized currently (authorized=1)"
Report "usb_authorized_device[]=${device}"
fi
else
LogText "Test: no authorized or authorized_default file, assuming ${device} is authorized by default"
Report "usb_authorized_default_device[]=${device}"
FOUND=1
fi
done
if [ ${FOUND} -eq 1 ]; then
LogText "Result: Some USB devices are authorized by default (or temporary) to connect to the system"
Display --indent 2 --text "- Checking USB devices authorization" --result "${STATUS_ENABLED}" --color YELLOW
# TODO: create documentation and enable the suggestion
#if [ ${USBGUARD_FOUND} -eq 0 ]; then
# ReportSuggestion "${TEST_NO}" "Disable USB devices authorization, to prevent unauthorized storage or data theft"
#fi
AddHP 0 3
else
LogText "Result: None USB devices are authorized by default (or temporary) to connect to the system"
Display --indent 2 --text "- Checking USB devices authorization" --result "${STATUS_DISABLED}" --color GREEN
AddHP 3 3
fi
else
LogText "Result: devices path does not exist"
fi
fi
#
#################################################################################
#
# Test : USB-3000
# Description : Perform USBGuard check
Register --test-no USB-3000 --os Linux --weight L --network NO --category security --description "Check for presence of USBGuard"
if [ ${SKIPTEST} -eq 0 ]; then
if [ ${USBGUARD_FOUND} -eq 1 ]; then
LogText "Result: USBGuard is installed (${USBGUARDBINARY})"
Display --indent 2 --text "- Checking USBGuard" --result "${STATUS_FOUND}" --color GREEN
AddHP 1 1
LogText "Checking USBGuard configuration file"
if [ -f ${ROOTDIR}etc/usbguard/usbguard-daemon.conf ]; then
USBGUARD_CONFIG="${ROOTDIR}etc/usbguard/usbguard-daemon.conf"
else
USBGUARD_CONFIG=""
fi
if [ -n "${USBGUARD_CONFIG}" ]; then
LogText "Result: USBGuard configuration found (${USBGUARD_CONFIG})"
Display --indent 4 --text "- Configuration" --result "${STATUS_FOUND}" --color GREEN
AddHP 1 1
LogText "Checking USBGuard restore controller device state (RestoreControllerDeviceState)"
USBGUARD_RESTORE_POLICY=$(${AWKBINARY} -F '=' -v OPT="RestoreControllerDeviceState" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_RESTORE_POLICY}" ]; then
LogText "Result: RestoreControllerDeviceState = ${USBGUARD_RESTORE_POLICY}"
case "${USBGUARD_RESTORE_POLICY}" in
"true")
Display --indent 6 --text "- Restore controller device state" --result "${USBGUARD_RESTORE_POLICY}" --color YELLOW
LogText " Consider changing RestoreControllerDeviceState to \"false\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Consider hardening USBGuard configuration" "RestoreControllerDeviceState (${USBGUARD_RESTORE_POLICY} --> false)"
AddHP 0 1
;;
"false")
Display --indent 6 --text "- Restore controller device state" --result "${USBGUARD_RESTORE_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for RestoreControllerDeviceState"
Display --indent 6 --text "- Restore controller device state" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Fix USBGuard configuration" "RestoreControllerDeviceState invalid \"${USBGUARD_RESTORE_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: RestoreControllerDeviceState not found"
Display --indent 6 --text "- Restore controller device state" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking USBGuard rule for controllers connected before daemon starts (PresentControllerPolicy)"
USBGUARD_CONTROLLER_POLICY=$(${AWKBINARY} -F '=' -v OPT="PresentControllerPolicy" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_CONTROLLER_POLICY}" ]; then
LogText "Result: PresentControllerPolicy = ${USBGUARD_CONTROLLER_POLICY}"
case "${USBGUARD_CONTROLLER_POLICY}" in
"allow" | "keep")
Display --indent 6 --text "- Rule for controllers connected before daemon starts" --result "${USBGUARD_CONTROLLER_POLICY}" --color YELLOW
LogText " Consider changing PresentControllerPolicy to \"apply-policy\", \"block\" or \"reject\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Consider hardening USBGuard configuration" "PresentControllerPolicy (${USBGUARD_CONTROLLER_POLICY} --> (apply-policy|block|reject)"
AddHP 0 1
;;
"apply-policy" | "block" | "reject")
Display --indent 6 --text "- Rule for controllers connected before daemon starts" --result "${USBGUARD_CONTROLLER_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for PresentControllerPolicy"
Display --indent 6 --text "- Rule for controllers connected before daemon starts" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Fix USBGuard configuration" "PresentControllerPolicy invalid \"${USBGUARD_CONTROLLER_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: PresentControllerPolicy not found"
Display --indent 6 --text "- Rule for controllers connected before daemon starts" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking USBGuard rule for devices connected before daemon starts (PresentDevicePolicy)"
USBGUARD_DEVICE_POLICY=$(${AWKBINARY} -F '=' -v OPT="PresentDevicePolicy" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_DEVICE_POLICY}" ]; then
LogText "Result: PresentDevicePolicy = ${USBGUARD_DEVICE_POLICY}"
case "${USBGUARD_DEVICE_POLICY}" in
"allow" | "keep")
Display --indent 6 --text "- Rule for devices connected before daemon starts" --result "${USBGUARD_DEVICE_POLICY}" --color YELLOW
LogText " Consider changing PresentDevicePolicy to \"apply-policy\", \"block\" or \"reject\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Consider hardening USBGuard configuration" "PresentDevicePolicy (${USBGUARD_DEVICE_POLICY} --> (apply-policy|block|reject)"
AddHP 0 1
;;
"apply-policy" | "block" | "reject")
Display --indent 6 --text "- Rule for devices connected before daemon starts" --result "${USBGUARD_DEVICE_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for PresentDevicePolicy"
Display --indent 6 --text "- Rule for devices connected before daemon starts" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Fix USBGuard configuration" "PresentDevicePolicy invalid \"${USBGUARD_DEVICE_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: PresentDevicePolicy not found"
Display --indent 6 --text "- Rule for devices connected before daemon starts" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking USBGuard rule for devices inserted after daemon starts (InsertedDevicePolicy)"
USBGUARD_INSERTED_POLICY=$(${AWKBINARY} -F '=' -v OPT="InsertedDevicePolicy" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_INSERTED_POLICY}" ]; then
LogText "Result: InsertedDevicePolicy = ${USBGUARD_INSERTED_POLICY}"
case "${USBGUARD_INSERTED_POLICY}" in
"allow" | "keep")
Display --indent 6 --text "- Rule for devices inserted after daemon starts" --result "${USBGUARD_INSERTED_POLICY}" --color YELLOW
LogText " Consider changing InsertedDevicePolicy to \"apply-policy\", \"block\" or \"reject\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Consider hardening USBGuard configuration" "InsertedDevicePolicy (${USBGUARD_INSERTED_POLICY} --> (apply-policy|block|reject)"
AddHP 0 1
;;
"apply-policy" | "block" | "reject")
Display --indent 6 --text "- Rule for devices inserted after daemon starts" --result "${USBGUARD_INSERTED_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for InsertedDevicePolicy"
Display --indent 6 --text "- Rule for devices inserted after daemon starts" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Fix USBGuard configuration" "InsertedDevicePolicy invalid \"${USBGUARD_INSERTED_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: InsertedDevicePolicy not found"
Display --indent 6 --text "- Rule for devices inserted after daemon starts" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking USBGuard rule for devices not in RuleFile (ImplicitPolicyTarget)"
USBGUARD_DEFAULT_POLICY=$(${AWKBINARY} -F '=' -v OPT="ImplicitPolicyTarget" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_DEFAULT_POLICY}" ]; then
LogText "Result: ImplicitPolicyTarget = ${USBGUARD_DEFAULT_POLICY}"
case "${USBGUARD_DEFAULT_POLICY}" in
"allow")
Display --indent 6 --text "- Rule for devices not in RuleFile" --result "${USBGUARD_DEFAULT_POLICY}" --color YELLOW
LogText " Consider changing ImplicitPolicyTarget to \"block\" or \"reject\""
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Consider hardening USBGuard configuration" "ImplicitPolicyTarget (${USBGUARD_DEFAULT_POLICY} --> (block|reject)"
AddHP 0 1
;;
"block"|"reject")
Display --indent 6 --text "- Rule for devices not in RuleFile" --result "${USBGUARD_DEFAULT_POLICY}" --color GREEN
AddHP 1 1
;;
*)
LogText "Result: Invalid configuration for ImplicitPolicyTarget"
Display --indent 6 --text "- Rule for devices not in RuleFile" --result "Invalid" --color RED
# TODO: assign TEST_NO, create documentation, and enable the suggestion
# ReportSuggestion "${TEST_NO}" "Fix USBGuard configuration" "ImplicitPolicyTarget invalid \"${USBGUARD_DEFAULT_POLICY}\""
AddHP 0 1
;;
esac
else
LogText "Result: ImplicitPolicyTarget not found"
Display --indent 4 --text "- Rule for devices not in RuleFile" --result "NOT FOUND" --color WHITE
AddHP 0 1
fi
LogText "Checking RuleFile"
USBGUARD_RULES=$(${AWKBINARY} -F '=' -v OPT="RuleFile" 'index($0, OPT) == 1 {print $2}' ${USBGUARD_CONFIG})
if [ -n "${USBGUARD_RULES}" ] && [ -f "${USBGUARD_RULES}" ]; then
LogText "Result: RuleFile found (${USBGUARD_RULES})"
Display --indent 4 --text "- RuleFile" --result "${STATUS_FOUND}" --color GREEN
AddHP 1 1
USBGUARD_RULES_ALLOW=$(${GREPBINARY} -E -c "^allow" ${USBGUARD_RULES})
Display --indent 6 --text "- Controllers & Devices allow" --result "${USBGUARD_RULES_ALLOW}" --color WHITE
USBGUARD_RULES_BLOCK=$(${GREPBINARY} -E -c "^block" ${USBGUARD_RULES})
Display --indent 6 --text "- Controllers & Devices block" --result "${USBGUARD_RULES_BLOCK}" --color WHITE
USBGUARD_RULES_REJECT=$(${GREPBINARY} -E -c "^reject" ${USBGUARD_RULES})
Display --indent 6 --text "- Controllers & Devices reject" --result "${USBGUARD_RULES_REJECT}" --color WHITE
else
LogText "Result: RuleFile not found (\"man usbguard\" for instructions to install initial policies)"
Display --indent 4 --text "- RuleFile" --result "${STATUS_NOT_FOUND}" --color RED
# To-Be-Added: assign TEST_NO, create documentation, and enable the suggestion
#ReportSuggestion "${TEST_NO}" "Install USBGuard RuleFile" "\"man usbguard\" for instructions to install initial policies"
AddHP 0 1
fi
else
Display --indent 4 --text "- Configuration" --result "${STATUS_NOT_FOUND}" --color WHITE
LogText "Result: Configuration not found"
# To-Be-Added: assign TEST_NO, create documentation, and enable the suggestion
#ReportSuggestion "${TEST_NO}" "USBGuard configuration file not found, consider reinstalling"
AddHP 0 7
fi
else
LogText "Result: USBGuard not found"
Display --indent 2 --text "- Checking USBGuard" --result "${STATUS_NOT_FOUND}" --color WHITE
# To-Be-Added: assign TEST_NO, create documentation, and enable the suggestion
#ReportSuggestion "${TEST_NO}" "Install USBGuard to allow for fine-grained control of USB authorization"
AddHP 0 8
fi
fi
#
#################################################################################
#
WaitForKeyPress
#
#================================================================================
# Lynis - Security Auditing and System Hardening for Linux and UNIX - https://cisofy.com
|
