debian-cis/bin/hardening/3.1.1_disable_ip_forwarding.sh
2020-12-07 14:53:10 +01:00

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#!/bin/bash
# run-shellcheck
#
# CIS Debian Hardening
#
#
# 3.1.1 Ensure IP forwarding is disabled (Scored)
#
set -e # One error, it's over
set -u # One variable unset, it's over
# shellcheck disable=2034
HARDENING_LEVEL=3
# shellcheck disable=2034
HARDENING_EXCEPTION=gw
# shellcheck disable=2034
DESCRIPTION="Disable IP forwarding."
SYSCTL_PARAMS='net.ipv4.ip_forward net.ipv6.conf.all.forwarding'
SYSCTL_EXP_RESULT=0
# This function will be called if the script status is on enabled / audit mode
audit() {
for SYSCTL_PARAM in $SYSCTL_PARAMS; do
does_sysctl_param_exists "net.ipv6"
if [ "$FNRET" = 0 ] || [[ ! $SYSCTL_PARAM =~ .*ipv6.* ]]; then # IPv6 is enabled or SYSCTL_VALUES doesn't contain ipv6
has_sysctl_param_expected_result "$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
fi
done
}
# This function will be called if the script status is on enabled mode
apply() {
for SYSCTL_PARAM in $SYSCTL_PARAMS; do
has_sysctl_param_expected_result "$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 $SYSCTL_EXP_RESULT"
fi
done
}
# This function will check config parameters required
check_config() {
:
}
# Source Root Dir Parameter
if [ -r /etc/default/cis-hardening ]; then
# shellcheck source=../../debian/default
. /etc/default/cis-hardening
fi
if [ -z "$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 "$CIS_ROOT_DIR"/lib/main.sh ]; then
# shellcheck source=../../lib/main.sh
. "$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