#!/bin/bash # run-shellcheck # # CIS Debian Hardening # # # 3.2.4 Ensure suspicious packets are logged (Scored) # set -e # One error, it's over set -u # One variable unset, it's over HARDENING_LEVEL=2 DESCRIPTION="Log suspicious packets, like spoofed packets." SYSCTL_PARAMS='net.ipv4.conf.all.log_martians=1 net.ipv4.conf.default.log_martians=1' # This function will be called if the script status is on enabled / audit mode audit () { for SYSCTL_VALUES in $SYSCTL_PARAMS; do SYSCTL_PARAM=$(echo $SYSCTL_VALUES | cut -d= -f 1) SYSCTL_EXP_RESULT=$(echo $SYSCTL_VALUES | cut -d= -f 2) debug "$SYSCTL_PARAM should be set to $SYSCTL_EXP_RESULT" has_sysctl_param_expected_result $SYSCTL_PARAM $SYSCTL_EXP_RESULT if [ $FNRET != 0 ]; then crit "$SYSCTL_PARAM was not set to $SYSCTL_EXP_RESULT" elif [ $FNRET = 255 ]; then warn "$SYSCTL_PARAM does not exist -- Typo?" else ok "$SYSCTL_PARAM correctly set to $SYSCTL_EXP_RESULT" fi done } # This function will be called if the script status is on enabled mode apply () { for SYSCTL_VALUES in $SYSCTL_PARAMS; do SYSCTL_PARAM=$(echo $SYSCTL_VALUES | cut -d= -f 1) SYSCTL_EXP_RESULT=$(echo $SYSCTL_VALUES | cut -d= -f 2) debug "$SYSCTL_PARAM should be set to $SYSCTL_EXP_RESULT" has_sysctl_param_expected_result $SYSCTL_PARAM $SYSCTL_EXP_RESULT if [ $FNRET != 0 ]; then warn "$SYSCTL_PARAM was not set to $SYSCTL_EXP_RESULT -- Fixing" set_sysctl_param $SYSCTL_PARAM $SYSCTL_EXP_RESULT sysctl -w net.ipv4.route.flush=1 > /dev/null elif [ $FNRET = 255 ]; then warn "$SYSCTL_PARAM does not exist -- Typo?" else ok "$SYSCTL_PARAM correctly set to $SYSCTL_EXP_RESULT" fi done } # This function will check config parameters required check_config() { : } # Source Root Dir Parameter if [ -r /etc/default/cis-hardening ]; then . /etc/default/cis-hardening fi if [ -z "$CIS_ROOT_DIR" ]; then echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment." echo "Cannot source CIS_ROOT_DIR variable, aborting." exit 128 fi # Main function, will call the proper functions given the configuration (audit, enabled, disabled) if [ -r $CIS_ROOT_DIR/lib/main.sh ]; then . $CIS_ROOT_DIR/lib/main.sh else echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_ROOT_DIR in /etc/default/cis-hardening" exit 128 fi