#!/bin/sh ################################################################################# # # Lynis # ------------------ # # Copyright 2007-2015, Michael Boelen, CISOfy (michael.boelen@cisofy.com) # Web site: https://cisofy.com # # 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. # ################################################################################# # # Firewalls # ################################################################################# # InsertSection "Software: firewalls" # ################################################################################# # IPTABLES_ACTIVE=0 IPTABLES_INKERNEL_ACTIVE=0 IPTABLES_MODULE_ACTIVE=0 FIREWALL_ACTIVE=0 FIREWALL_SOFTWARE="" # ################################################################################# # # Test : FIRE-4511 # Description : Check iptables kernel module Register --test-no FIRE-4511 --os Linux --weight L --network NO --description "Check iptables kernel module" if [ ${SKIPTEST} -eq 0 ]; then FIND=`lsmod | awk '{ print $1 }' | grep "^ip*_tables"` if [ ! "${FIND}" = "" ]; then FIREWALL_ACTIVE=1 FIREWALL_SOFTWARE="iptables" IPTABLES_ACTIVE=1 IPTABLES_MODULE_ACTIVE=1 Display --indent 2 --text "- Checking iptables kernel module" --result FOUND --color GREEN logtext "Result: Found iptables in loaded kernel modules" for I in ${FIND}; do logtext "Found module: ${I}" done else Display --indent 2 --text "- Checking iptables kernel module" --result "NOT FOUND" --color WHITE # If we can't find an active module, try to find the Linux configuration file and check that if [ -f /proc/config.gz ]; then LINUXCONFIGFILE="/proc/config.gz"; tCATCMD="zcat"; fi sLINUXCONFIGFILE="/boot/config-`uname -r`" if [ -f ${sLINUXCONFIGFILE} ]; then LINUXCONFIGFILE=${sLINUXCONFIGFILE}; tCATCMD="cat"; fi # If we have a kernel configuration file, use it for testing # Do not perform test if we already found it in kernel module list, to avoid triggered it in the upcoming # tests, when using iptables --list if [ ! "${LINUXCONFIGFILE}" = "" ]; then if [ -f ${LINUXCONFIGFILE} -a ${IPTABLES_MODULE_ACTIVE} -eq 0 ]; then logtext "Result: found kernel configuration file (${LINUXCONFIGFILE})" FIND=`${tCATCMD} ${LINUXCONFIGFILE} | grep -v '^#' | grep "CONFIG_IP_NF_IPTABLES" | head -n 1` if [ ! "${FIND}" = "" ]; then HAVEMOD=`echo ${FIND} | cut -d '=' -f2` # Do not use iptables if it's compiled as a module (=m), since we already tested for it in the # active list. if [ "${HAVEMOD}" = "y" ]; then logtext "Result: iptables available as a module in the configuration" IPTABLES_ACTIVE=1 IPTABLES_INKERNEL_ACTIVE=1 FIREWALL_ACTIVE=1 FIREWALL_SOFTWARE="iptables" Display --indent 2 --text "- Checking iptables in config file" --result FOUND --color GREEN else logtext "Result: no iptables found in Linux kernel config file" fi else logtext "Result: no Linux configuration file found" Display --indent 2 --text "- Checking iptables in config file" --result "NOT FOUND" --color WHITE fi fi fi fi fi # ################################################################################# # # Test : FIRE-4512 # Description : Check iptables for empty ruleset if [ ! "${IPTABLESBINARY}" = "" -a ${IPTABLES_ACTIVE} -eq 1 ]; then PREQS_MET="YES"; else PREQS_MET="NO"; fi Register --test-no FIRE-4512 --preqs-met ${PREQS_MET} --os Linux --weight L --network NO --root-only YES --description "Check iptables for empty ruleset" if [ ${SKIPTEST} -eq 0 ]; then FIND=`${IPTABLESBINARY} --list --numeric | egrep -v "^(Chain|target|$)" | wc -l | tr -d ' '` if [ "${FIND}" = "0" ]; then # Firewall is active, but clearly needs configuration FIREWALL_ACTIVE=1 logtext "Result: iptables ruleset is empty" Display --indent 4 --text "- Checking for empty ruleset" --result WARNING --color RED ReportWarning ${TEST_NO} "L" "iptables module(s) loaded, but no rules active" ReportSuggestion ${TEST_NO} "Disable iptables kernel module if not used or make sure rules are being used" else logtext "Result: one or more rules are available" Display --indent 4 --text "- Checking for empty ruleset" --result OK --color GREEN fi fi # ################################################################################# # # Test : FIRE-4513 # Description : Check iptables for unused rules if [ ! "${IPTABLESBINARY}" = "" -a ${IPTABLES_ACTIVE} -eq 1 ]; then PREQS_MET="YES"; else PREQS_MET="NO"; fi Register --test-no FIRE-4513 --preqs-met ${PREQS_MET} --os Linux --weight L --network NO --root-only YES --description "Check iptables for unused rules" if [ ${SKIPTEST} -eq 0 ]; then FIND=`${IPTABLESBINARY} --list --numeric --line-numbers --verbose | awk '{ if ($2=="0") print $1 }' | xargs` if [ "${FIND}" = "" ]; then Display --indent 4 --text "- Checking for unused rules" --result OK --color GREEN logtext "Result: There are no unused rules present" else Display --indent 4 --text "- Checking for unused rules" --result WARNING --color YELLOW logtext "Result: Found one or more possible unused rules" logtext "Description: Unused rules can be a sign that the firewall rules aren't optimized or up-to-date" logtext "Note: Sometimes rules aren't triggered but still in use. Keep this in mind before cleaning up rules." logtext "Output: iptables rule numbers: ${FIND}" #ReportWarning ${TEST_NO} "L" "Found possible unused iptables rules ($FIND)" ReportSuggestion ${TEST_NO} "Check iptables rules to see which rules are currently not used" logtext "Tip: iptables --list --numeric --line-numbers --verbose" fi fi # ################################################################################# # # Test : FIRE-4518 # Description : Checking status of pf firewall components Register --test-no FIRE-4518 --weight L --network NO --description "Check pf firewall components" if [ ${SKIPTEST} -eq 0 ]; then PFFOUND=0; PFLOGDFOUND=0 # Check status with pfctl logtext "Test: checking pf status via pfctl" if [ ! "${PFCTLBINARY}" = "" ]; then FIND=`${PFCTLBINARY} -sa 2>&1 | grep "^Status" | head -1 | awk '{ print $2 }'` if [ "${FIND}" = "Enabled" ]; then Display --indent 2 --text "- Checking pf status (pfctl)" --result ENABLED --color GREEN logtext "Result: pf is enabled" PFFOUND=1 AddHP 3 3 else if [ "${FIND}" = "Disabled" ]; then Display --indent 2 --text "- Checking pf status (pfctl)" --result DISABLED --color RED logtext "Result: pf is disabled" AddHP 0 3 else Display --indent 2 --text "- Checking pf status (pfctl)" --result UNKNOWN --color YELLOW ReportException ${TEST_NO} "Unknown status of pf firewall" fi fi fi # If we didn't find the status to be enabled, stop searching if [ ${PFFOUND} -eq 0 ]; then # Check for pf kernel module (FreeBSD and similar) logtext "Test: searching for pf kernel module" if [ ! "${KLDSTATBINARY}" = "" ]; then FIND=`${KLDSTATBINARY} | grep 'pf.ko'` if [ "${FIND}" = "" ]; then logtext "Result: Can not find pf KLD" else logtext "Result: pf KLD loaded" PFFOUND=1 fi else logtext "Result: no kldstat binary, skipping this part" fi IsRunning pflogd if [ ${RUNNING} -eq 1 ]; then logtext "Result: found pflog daemon in process list" Display --indent 4 --text "- Checking pflogd status" --result ACTIVE --color GREEN PFFOUND=1 PFLOGDFOUND=1 else logtext "Result: pflog daemon not found in process list" Display --indent 4 --text "- Checking pflogd status" --result "NOT FOUND" --color YELLOW fi fi if [ ${PFFOUND} -eq 1 ]; then FIREWALL_ACTIVE=1 FIREWALL_SOFTWARE="pf" else logtext "Result: pf not running on this system" Display --indent 2 --text "- Checking pf" --result "NOT FOUND" --color WHITE fi fi # ################################################################################# # # Test : FIRE-4520 # Description : Check pf configuration consistency if [ ${PFFOUND} -eq 1 ]; then PREQS_MET="YES"; else PREQS_MET="NO"; fi Register --test-no FIRE-4520 --preqs-met ${PREQS_MET} --weight L --network NO --description "Check pf configuration consistency" if [ ${SKIPTEST} -eq 0 ]; then logtext "Test: check /etc/pf.conf" # Test for warnings (-n don't load the rules) if [ -f /etc/pf.conf ]; then logtext "Result: /etc/pf.conf exists" # Check results from pfctl PFWARNINGS=`pfctl -n -f /etc/pf.conf -vvv 2>&1 | grep -i 'warning'` if [ "${PFWARNINGS}" = "" ]; then Display --indent 4 --text "- Checking pf configuration consistency" --result OK --color GREEN logtext "Result: no pf filter warnings found" else Display --indent 4 --text "- Checking pf configuration consistency" --result WARNING --color RED logtext "Result: found one or more warnings in the pf filter rules" ReportWarning ${TEST_NO} "H" "Found one or more warnings in pf configuration file" ReportSuggestion ${TEST_NO} "Run 'pfctl -n -f /etc/pf.conf -vvv' to see available pf warnings" fi else logtext "Result: /etc/pf.conf does NOT exist" fi fi # ################################################################################# # # Test : FIRE-4522 # Description : Check ipchains # ################################################################################# # # Test : FIRE-4524 # Description : Check for CSF (ConfigServer Security & Firewall) Register --test-no FIRE-4524 --weight L --network NO --description "Check for CSF presence" if [ ${SKIPTEST} -eq 0 ]; then FILE="/etc/csf/csf.conf" logtext "Test: check ${FILE}" if [ -f ${FILE} ]; then logtext "Result: ${FILE} exists" FIREWALL_ACTIVE=1 FIREWALL_SOFTWARE="csf" Display --indent 2 --text "- Checking CSF status (configuration file)" --result FOUND --color GREEN else logtext "Result: ${FILE} does NOT exist" fi fi # ################################################################################# # # Test : FIRE-4526 # Description : Check ipf (Solaris) if [ ! "${IPFBINARY}" = "" ]; then PREQS_MET="YES"; else PREQS_MET="NO"; fi Register --test-no FIRE-4526 --os Solaris --preqs-met ${PREQS_MET} --weight L --network NO --description "Check ipf status" if [ ${SKIPTEST} -eq 0 ]; then FIND=`${IPFBINARY} -n -V | grep "^Running" | awk '{ print $2 }'` if [ "${FIND}" = "yes" ]; then Display --indent 4 --text "- Checking ipf status" --result RUNNING --color GREEN logtext "Result: ipf is enabled and running" FIREWALL_ACTIVE=1 FIREWALL_SOFTWARE="ipf" else Display --indent 4 --text "- Checking ipf status" --result "NOT RUNNING" --color YELLOW logtext "Result: ipf is not running" fi fi # ################################################################################# # # Test : FIRE-4530 # Description : Check ipfw # ################################################################################# # # Test : FIRE-4590 # Description : Check if at least one firewall if active Register --test-no FIRE-4590 --weight L --network NO --description "Check firewall status" if [ ${SKIPTEST} -eq 0 ]; then if [ ${FIREWALL_ACTIVE} -eq 1 ]; then Display --indent 2 --text "- Checking host based firewall" --result ACTIVE --color GREEN logtext "Result: host based firewall or packet filter is active" report "manual[]=Verify if there is a formal process for testing and applying firewall rules" report "manual[]=Verify all traffic is filtered the right way between the different security zones" report "manual[]=Verify if a list is available with all required services" # YYY Solaris ipf (determine default policy) report "manual[]=Make sure an explicit deny all is the default policy for all unmatched traffic" AddHP 5 5 else Display --indent 2 --text "- Checking host based firewall" --result "NOT ACTIVE" --color YELLOW logtext "Result: no host based firewall/packet filter found or configured" ReportSuggestion ${TEST_NO} "Configure a firewall/packet filter to filter incoming and outgoing traffic" AddHP 0 5 fi fi # ################################################################################# # # Report firewall installed for now, if we found one active. Next step would be determining binaries first and apply additional checks. report "firewall_installed=${FIREWALL_ACTIVE}" report "firewall_active=${FIREWALL_ACTIVE}" report "firewall_software=${FIREWALL_SOFTWARE}" wait_for_keypress # #================================================================================ # Lynis - Copyright 2007-2015, Michael Boelen, CISOfy - https://cisofy.com