From 4be1a9d9e401ac3669d18ffdbef28216bd266d77 Mon Sep 17 00:00:00 2001
From: damien cavagnini <damien.cavagnini@corp.ovh.com>
Date: Tue, 5 Aug 2025 16:23:52 +0200
Subject: [PATCH] feat: add debian12 scripts

- iptables_loopback.sh 			-> 4.3.2.2
- iptables_rule_them_all.sh 		-> 4.3.2.4
- iptables_outbound_established.sh 	-> 4.3.2.3
- ip6tables_loopback.sh			-> 4.3.3.2
- ip6tables_outbound_established.sh	-> 4.3.3.3
- ip6tables_rule_them_all.sh		-> 4.3.3.4
- ip6tables_default_deny_policy.sh 	-> 4.3.3.1
---
 .../ip6tables_default_deny_policy.sh          |  97 +++++++++++++++
 bin/hardening/ip6tables_loopback.sh           | 114 ++++++++++++++++++
 .../ip6tables_outbound_established.sh         |  92 ++++++++++++++
 bin/hardening/ip6tables_rule_them_all.sh      | 108 +++++++++++++++++
 bin/hardening/iptables_loopback.sh            | 108 +++++++++++++++++
 .../iptables_outbound_established.sh          |  86 +++++++++++++
 bin/hardening/iptables_rule_them_all.sh       | 102 ++++++++++++++++
 .../ip6tables_default_deny_policy.sh          |  16 +++
 tests/hardening/ip6tables_loopback.sh         |  16 +++
 .../ip6tables_outbound_established.sh         |  16 +++
 tests/hardening/ip6tables_rule_them_all.sh    |  16 +++
 tests/hardening/iptables_loopback.sh          |  16 +++
 .../iptables_outbound_established.sh          |  16 +++
 tests/hardening/iptables_rule_them_all.sh     |  16 +++
 14 files changed, 819 insertions(+)
 create mode 100644 bin/hardening/ip6tables_default_deny_policy.sh
 create mode 100755 bin/hardening/ip6tables_loopback.sh
 create mode 100755 bin/hardening/ip6tables_outbound_established.sh
 create mode 100755 bin/hardening/ip6tables_rule_them_all.sh
 create mode 100755 bin/hardening/iptables_loopback.sh
 create mode 100755 bin/hardening/iptables_outbound_established.sh
 create mode 100755 bin/hardening/iptables_rule_them_all.sh
 create mode 100644 tests/hardening/ip6tables_default_deny_policy.sh
 create mode 100644 tests/hardening/ip6tables_loopback.sh
 create mode 100644 tests/hardening/ip6tables_outbound_established.sh
 create mode 100644 tests/hardening/ip6tables_rule_them_all.sh
 create mode 100644 tests/hardening/iptables_loopback.sh
 create mode 100644 tests/hardening/iptables_outbound_established.sh
 create mode 100644 tests/hardening/iptables_rule_them_all.sh

diff --git a/bin/hardening/ip6tables_default_deny_policy.sh b/bin/hardening/ip6tables_default_deny_policy.sh
new file mode 100644
index 0000000..dfea79d
--- /dev/null
+++ b/bin/hardening/ip6tables_default_deny_policy.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure ip6tables default deny firewall policy (Manual)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=2
+# shellcheck disable=2034
+DESCRIPTION="Ensure ip6tables default deny firewall policy"
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    INPUT_CHAIN_DROP=1
+    OUTPUT_CHAIN_DROP=1
+    FORWARD_CHAIN_DROP=1
+
+    local input_default=""
+    local output_default=""
+    local forward_default=""
+    input_default=$($SUDO_CMD ip6tables -S INPUT | awk '/^-P/ {print $3}')
+    output_default=$($SUDO_CMD ip6tables -S OUTPUT | awk '/^-P/ {print $3}')
+    forward_default=$($SUDO_CMD ip6tables -S FORWARD | awk '/^-P/ {print $3}')
+
+    if [ "$input_default" != "DROP" ]; then
+        crit "ip6tables 'INPUT' chain does not have 'DROP' has default policy"
+    else
+        ok "ip6tables 'input' chain has 'DROP' has default policy"
+        INPUT_CHAIN_DROP=0
+    fi
+
+    if [ "$output_default" != "DROP" ]; then
+        crit "ip6tables 'OUTPUT' chain does not have 'DROP' has default policy"
+    else
+        ok "ip6tables 'OUTPUT' chain has 'DROP' has default policy"
+        OUTPUT_CHAIN_DROP=0
+    fi
+
+    if [ "$forward_default" != "DROP" ]; then
+        crit "ip6tables 'FORWARD' chain does not have 'DROP' has default policy"
+    else
+        ok "ip6tables 'FORWARD' chain has 'DROP' has default policy"
+        FORWARD_CHAIN_DROP=0
+    fi
+
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    audit
+    if [ "$INPUT_CHAIN_DROP" -ne 0 ]; then
+        info "Please review your ip6tables default 'INPUT' policy. We wont apply it for you to avoid cutting the branch you are sitting on"
+    fi
+
+    if [ "$OUTPUT_CHAIN_DROP" -ne 0 ]; then
+        info "Please review your ip6tables default 'OUTPUT' policy. We wont apply it for you to avoid cutting the branch you are sitting on"
+    fi
+
+    if [ "$FORWARD_CHAIN_DROP" -ne 0 ]; then
+        info "Please review your ip6tables default 'FORWARD' policy. We wont apply it for you to avoid cutting the branch you are sitting on"
+    fi
+
+}
+
+# This function will check config parameters required
+check_config() {
+    :
+}
+
+# Source Root Dir Parameter
+if [ -r /etc/default/cis-hardening ]; then
+    # shellcheck source=../../debian/default
+    . /etc/default/cis-hardening
+fi
+
+if [ -z "$CIS_LIB_DIR" ]; then
+    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
+    echo "Cannot source CIS_LIB_DIR variable, aborting."
+    exit 128
+fi
+
+# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
+if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
+    # shellcheck source=../../lib/main.sh
+    . "${CIS_LIB_DIR}"/main.sh
+else
+    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
+    exit 128
+fi
diff --git a/bin/hardening/ip6tables_loopback.sh b/bin/hardening/ip6tables_loopback.sh
new file mode 100755
index 0000000..346e6e1
--- /dev/null
+++ b/bin/hardening/ip6tables_loopback.sh
@@ -0,0 +1,114 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure ip6tables loopback traffic is configured (Automated)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=2
+# shellcheck disable=2034
+DESCRIPTION="Ensure ip6tables loopback traffic is configured"
+PACKAGE="iptables"
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    is_pkg_installed "$PACKAGE"
+    if [ "$FNRET" -ne 0 ]; then
+        crit "$PACKAGE is not installed"
+        return
+    fi
+
+    is_ipv6_enabled
+    if [ "$NFRET" -ne 0 ]; then
+        ok "ipv6 is not enabled"
+        return
+    fi
+
+    IPTABLES_LOOPBACK_INPUT=1
+    IPTABLES_LOOPBACK_OUTPUT=1
+    IPTABLES_LOOPBACK_DENY=1
+
+    local input_rules
+    local output_rules
+    input_rules=$($SUDO_CMD ip6tables -S INPUT 2>/dev/null)
+    output_rules=$($SUDO_CMD ip6tables -S OUTPUT 2>/dev/null)
+
+    # the '.*' below is in case of comments
+    # shellcheck disable=2086
+    if grep "\-A INPUT -i lo.*-j ACCEPT" <<<$input_rules >/dev/null; then
+        ok "loopback is configured in ip6tables input rules"
+        IPTABLES_LOOPBACK_INPUT=0
+    else
+        crit "loopback is not configured in ip6tables input rules"
+    fi
+
+    # shellcheck disable=2086
+    if grep "\-A INPUT -s ::1 .*-j DROP" <<<$input_rules >/dev/null; then
+        ok "::1 is dropped in ip6tables input rules"
+        IPTABLES_LOOPBACK_DENY=0
+    else
+        crit "::1 is not dropped in ip6tables input rules"
+    fi
+
+    # shellcheck disable=2086
+    if grep "\-A OUTPUT -o lo.*-j ACCEPT" <<<$output_rules >/dev/null; then
+        ok "loopback is configured in ip6tables output rules"
+        IPTABLES_LOOPBACK_OUTPUT=0
+    else
+        crit "loopback is not configured in ip6tables output rules"
+    fi
+
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    audit
+    if [ "$IPTABLES_LOOPBACK_INPUT" -ne 0 ]; then
+        info "update ip6tables rules to allow loopback input"
+        ip6tables -A INPUT -i lo -j ACCEPT
+    fi
+
+    if [ "$IPTABLES_LOOPBACK_OUTPUT" -ne 0 ]; then
+        info "update ip6tables rules to allow loopback" output
+        ip6tables -A OUTPUT -o lo -j ACCEPT
+    fi
+
+    if [ "$IPTABLES_LOOPBACK_DENY" -ne 0 ]; then
+        info "update ip6tables rules to drop ::1  input"
+        ip6tables -A INPUT -s ::1 -j DROP
+    fi
+}
+
+# This function will check config parameters required
+check_config() {
+    :
+}
+
+# Source Root Dir Parameter
+if [ -r /etc/default/cis-hardening ]; then
+    # shellcheck source=../../debian/default
+    . /etc/default/cis-hardening
+fi
+
+if [ -z "$CIS_LIB_DIR" ]; then
+    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
+    echo "Cannot source CIS_LIB_DIR variable, aborting."
+    exit 128
+fi
+
+# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
+if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
+    # shellcheck source=../../lib/main.sh
+    . "${CIS_LIB_DIR}"/main.sh
+else
+    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
+    exit 128
+fi
diff --git a/bin/hardening/ip6tables_outbound_established.sh b/bin/hardening/ip6tables_outbound_established.sh
new file mode 100755
index 0000000..b509680
--- /dev/null
+++ b/bin/hardening/ip6tables_outbound_established.sh
@@ -0,0 +1,92 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure ip6tables outbound and established connections are configured (Manual)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=2
+# shellcheck disable=2034
+DESCRIPTION="Ensure ip6tables outbound and established connections are configured"
+PACKAGE="iptables"
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    is_pkg_installed "$PACKAGE"
+    if [ "$FNRET" -ne 0 ]; then
+        crit "$PACKAGE is not installed"
+        return
+    fi
+
+    is_ipv6_enabled
+    if [ "$NFRET" -ne 0 ]; then
+        ok "ipv6 is not enabled"
+        return
+    fi
+
+    INPUT_ESTABLISHED=1
+    OUTPUT_ESTABLISHED=1
+
+    local output_established_rules
+
+    if $SUDO_CMD ip6tables -S INPUT | grep ESTABLISHED >/dev/null 2>&1; then
+        INPUT_ESTABLISHED=0
+        ok "INPUT ESTABLISHED connections are allowed"
+    else
+        crit "INPUT ESTABLISHED connections are not allowed"
+    fi
+
+    if $SUDO_CMD ip6tables -S OUTPUT | grep state >/dev/null 2>&1; then
+        output_established_rules=$($SUDO_CMD ip6tables -S OUTPUT | grep state)
+        # shellcheck disable=2086
+        if grep ESTABLISHED <<<$output_established_rules >/dev/null && grep NEW <<<$output_established_rules >/dev/null; then
+            OUTPUT_ESTABLISHED=0
+            ok "OUTPUT NEW and ESTABLISHED connections are allowed"
+        else
+            crit "OUTPUT NEW and ESTABLISHED connections are not allowed"
+        fi
+    else
+        crit "OUTPUT NEW and ESTABLISHED connections are not allowed"
+    fi
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    if [ "$INPUT_ESTABLISHED" -ne 0 ] || [ "$OUTPUT_ESTABLISHED" -ne 0 ]; then
+        info "Please review manually your outbound and established connection, and update them accordingly to your site policies"
+    fi
+}
+
+# This function will check config parameters required
+check_config() {
+    :
+}
+
+# Source Root Dir Parameter
+if [ -r /etc/default/cis-hardening ]; then
+    # shellcheck source=../../debian/default
+    . /etc/default/cis-hardening
+fi
+
+if [ -z "$CIS_LIB_DIR" ]; then
+    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
+    echo "Cannot source CIS_LIB_DIR variable, aborting."
+    exit 128
+fi
+
+# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
+if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
+    # shellcheck source=../../lib/main.sh
+    . "${CIS_LIB_DIR}"/main.sh
+else
+    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
+    exit 128
+fi
diff --git a/bin/hardening/ip6tables_rule_them_all.sh b/bin/hardening/ip6tables_rule_them_all.sh
new file mode 100755
index 0000000..649ed54
--- /dev/null
+++ b/bin/hardening/ip6tables_rule_them_all.sh
@@ -0,0 +1,108 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure ip6tables firewall rules exist for all open ports (Manual)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=2
+# shellcheck disable=2034
+DESCRIPTION="Ensure ip6tables firewall rules exist for all open ports"
+PACKAGE="iptables"
+
+# we are going to
+# - list listening ports
+# - list ip6tables rules using dport
+# - compare both
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    is_pkg_installed "$PACKAGE"
+    if [ "$FNRET" -ne 0 ]; then
+        crit "$PACKAGE is not installed"
+        return
+    fi
+
+    is_ipv6_enabled
+    if [ "$NFRET" -ne 0 ]; then
+        ok "ipv6 is not enabled"
+        return
+    fi
+
+    IPTABLES_IS_VALID=0
+    local iptables_ports_rules=""
+    local listening_ports
+    # we may have configured some custom chains in INPUT, that need to be checked too.
+    local custom_chains=""
+    local builtin_targets="ACCEPT DROP QUEUE RETURN"
+
+    for target in $($SUDO_CMD ip6tables -L INPUT | awk '{print $1}' | sed '1,2d'); do
+        if ! grep "$target" <<<"$builtin_targets" >/dev/null; then
+            custom_chains="$custom_chains $target"
+        fi
+    done
+
+    for chain in INPUT $custom_chains; do
+        # number of fields is not fixed, there may be some comments before and after
+        # ex:
+        # udp spt:68 dpt:67 /* DHCP Request */
+        # /* ssh connection */ tcp dpt:22
+        iptables_ports_rules="$iptables_ports_rules $($SUDO_CMD ip6tables -nL "$chain" | grep 'dpt:' | sed 's/^.*dpt://g' | awk '{print $1}' | sort -u)"
+    done
+    listening_ports=$($SUDO_CMD ss -tuln | awk '($5!~/%lo:/ && $5!~/127.0.0.1:/ && $5!~/\[?::1\]?:/) {split($5, a, ":"); print a[2]}' | sort -u)
+
+    for port in $listening_ports; do
+        if ! grep "$port" <<<"$iptables_ports_rules" >/dev/null; then
+            crit "$port does not have an ip6tables rule"
+            IPTABLES_IS_VALID=1
+        fi
+    done
+
+    if [ "$IPTABLES_IS_VALID" -eq 0 ]; then
+        ok "all listening ports have a corresponding rule in ufw"
+    fi
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    audit
+    if [ "$IPTABLES_IS_VALID" -ne 0 ]; then
+        # Debian 12 CIS marks this script as "Automated", but we wont do it
+        # How can we know if a rule should be allowed or denied ? From everywhere ? A specific range ?
+        warn "Please review the ip6tables rules and update them accordingly. We wont do it in an automated way, as we don't know if it should be allowed or denied"
+    fi
+
+}
+
+# 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 "$CIS_LIB_DIR" ]; then
+    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
+    echo "Cannot source CIS_LIB_DIR variable, aborting."
+    exit 128
+fi
+
+# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
+if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
+    # shellcheck source=../../lib/main.sh
+    . "${CIS_LIB_DIR}"/main.sh
+else
+    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
+    exit 128
+fi
diff --git a/bin/hardening/iptables_loopback.sh b/bin/hardening/iptables_loopback.sh
new file mode 100755
index 0000000..8c475ad
--- /dev/null
+++ b/bin/hardening/iptables_loopback.sh
@@ -0,0 +1,108 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure iptables loopback traffic is configured (Automated)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=2
+# shellcheck disable=2034
+DESCRIPTION="Ensure iptables loopback traffic is configured"
+PACKAGE="iptables"
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    is_pkg_installed "$PACKAGE"
+    if [ "$FNRET" -ne 0 ]; then
+        crit "$PACKAGE is not installed"
+        return
+    fi
+
+    IPTABLES_LOOPBACK_INPUT=1
+    IPTABLES_LOOPBACK_OUTPUT=1
+    IPTABLES_LOOPBACK_DENY=1
+
+    local input_rules
+    local output_rules
+    input_rules=$($SUDO_CMD iptables -S INPUT 2>/dev/null)
+    output_rules=$($SUDO_CMD iptables -S OUTPUT 2>/dev/null)
+
+    # the '.*' below is in case of comments
+    # shellcheck disable=2086
+    if grep "\-A INPUT -i lo.*-j ACCEPT" <<<$input_rules >/dev/null; then
+        ok "loopback is configured in iptables input rules"
+        IPTABLES_LOOPBACK_INPUT=0
+    else
+        crit "loopback is not configured in iptables input rules"
+    fi
+
+    # shellcheck disable=2086
+    if grep "\-A INPUT -s 127.0.0.0/8.*-j DROP" <<<$input_rules >/dev/null; then
+        ok "127.0.0.0/8 is dropped in iptables input rules"
+        IPTABLES_LOOPBACK_DENY=0
+    else
+        crit "127.0.0.0/8 is not dropped in iptables input rules"
+    fi
+
+    # shellcheck disable=2086
+    if grep "\-A OUTPUT -o lo.*-j ACCEPT" <<<$output_rules >/dev/null; then
+        ok "loopback is configured in iptables output rules"
+        IPTABLES_LOOPBACK_OUTPUT=0
+    else
+        crit "loopback is not configured in iptables output rules"
+    fi
+
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    audit
+    if [ "$IPTABLES_LOOPBACK_INPUT" -ne 0 ]; then
+        info "update iptables rules to allow loopback input"
+        iptables -A INPUT -i lo -j ACCEPT
+    fi
+
+    if [ "$IPTABLES_LOOPBACK_OUTPUT" -ne 0 ]; then
+        info "update iptables rules to allow loopback" output
+        iptables -A OUTPUT -o lo -j ACCEPT
+    fi
+
+    if [ "$IPTABLES_LOOPBACK_DENY" -ne 0 ]; then
+        info "update iptables rules to drop 127.0.0.0/8 input"
+        iptables -A INPUT -s 127.0.0.0/8 -j DROP
+    fi
+}
+
+# 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 "$CIS_LIB_DIR" ]; then
+    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
+    echo "Cannot source CIS_LIB_DIR variable, aborting."
+    exit 128
+fi
+
+# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
+if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
+    # shellcheck source=../../lib/main.sh
+    . "${CIS_LIB_DIR}"/main.sh
+else
+    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
+    exit 128
+fi
diff --git a/bin/hardening/iptables_outbound_established.sh b/bin/hardening/iptables_outbound_established.sh
new file mode 100755
index 0000000..fcdc97f
--- /dev/null
+++ b/bin/hardening/iptables_outbound_established.sh
@@ -0,0 +1,86 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure iptables outbound and established connections are configured (Manual)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=2
+# shellcheck disable=2034
+DESCRIPTION="Ensure iptables outbound and established connections are configured"
+PACKAGE="iptables"
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    is_pkg_installed "$PACKAGE"
+    if [ "$FNRET" -ne 0 ]; then
+        crit "$PACKAGE is not installed"
+        return
+    fi
+
+    INPUT_ESTABLISHED=1
+    OUTPUT_ESTABLISHED=1
+
+    local output_established_rules
+
+    if $SUDO_CMD iptables -S INPUT | grep ESTABLISHED >/dev/null 2>&1; then
+        INPUT_ESTABLISHED=0
+        ok "INPUT ESTABLISHED connections are allowed"
+    else
+        crit "INPUT ESTABLISHED connections are not allowed"
+    fi
+
+    if $SUDO_CMD iptables -S OUTPUT | grep state >/dev/null 2>&1; then
+        output_established_rules=$($SUDO_CMD iptables -S OUTPUT | grep state)
+        # shellcheck disable=2086
+        if grep ESTABLISHED <<<$output_established_rules >/dev/null && grep NEW <<<$output_established_rules >/dev/null; then
+            OUTPUT_ESTABLISHED=0
+            ok "OUTPUT NEW and ESTABLISHED connections are allowed"
+        else
+            crit "OUTPUT NEW and ESTABLISHED connections are not allowed"
+        fi
+    else
+        crit "OUTPUT NEW and ESTABLISHED connections are not allowed"
+    fi
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    if [ "$INPUT_ESTABLISHED" -ne 0 ] || [ "$OUTPUT_ESTABLISHED" -ne 0 ]; then
+        info "Please review manually your outbound and established connection, and update them accordingly to your site policies"
+    fi
+}
+
+# This function will check config parameters required
+check_config() {
+    :
+}
+
+# Source Root Dir Parameter
+if [ -r /etc/default/cis-hardening ]; then
+    # shellcheck source=../../debian/default
+    . /etc/default/cis-hardening
+fi
+
+if [ -z "$CIS_LIB_DIR" ]; then
+    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
+    echo "Cannot source CIS_LIB_DIR variable, aborting."
+    exit 128
+fi
+
+# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
+if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
+    # shellcheck source=../../lib/main.sh
+    . "${CIS_LIB_DIR}"/main.sh
+else
+    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
+    exit 128
+fi
diff --git a/bin/hardening/iptables_rule_them_all.sh b/bin/hardening/iptables_rule_them_all.sh
new file mode 100755
index 0000000..8f2a91d
--- /dev/null
+++ b/bin/hardening/iptables_rule_them_all.sh
@@ -0,0 +1,102 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure iptables firewall rules exist for all open ports (Manual)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=2
+# shellcheck disable=2034
+DESCRIPTION="Ensure iptables firewall rules exist for all open ports"
+PACKAGE="iptables"
+
+# we are going to
+# - list listening ports
+# - list iptables rules using dport
+# - compare both
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    is_pkg_installed "$PACKAGE"
+    if [ "$FNRET" -ne 0 ]; then
+        crit "$PACKAGE is not installed"
+        return
+    fi
+
+    IPTABLES_IS_VALID=0
+    local iptables_ports_rules=""
+    local listening_ports
+    # we may have configured some custom chains in INPUT, that need to be checked too.
+    local custom_chains=""
+    local builtin_targets="ACCEPT DROP QUEUE RETURN"
+
+    for target in $($SUDO_CMD iptables -L INPUT | awk '{print $1}' | sed '1,2d'); do
+        if ! grep "$target" <<<"$builtin_targets" >/dev/null; then
+            custom_chains="$custom_chains $target"
+        fi
+    done
+
+    for chain in INPUT $custom_chains; do
+        # number of fields is not fixed, there may be some comments before and after
+        # ex:
+        # udp spt:68 dpt:67 /* DHCP Request */
+        # /* ssh connection */ tcp dpt:22
+        iptables_ports_rules="$iptables_ports_rules $($SUDO_CMD iptables -nL "$chain" | grep 'dpt:' | sed 's/^.*dpt://g' | awk '{print $1}' | sort -u)"
+    done
+    listening_ports=$($SUDO_CMD ss -tuln | awk '($5!~/%lo:/ && $5!~/127.0.0.1:/ && $5!~/\[?::1\]?:/) {split($5, a, ":"); print a[2]}' | sort -u)
+
+    for port in $listening_ports; do
+        if ! grep "$port" <<<"$iptables_ports_rules" >/dev/null; then
+            crit "$port does not have an iptables rule"
+            IPTABLES_IS_VALID=1
+        fi
+    done
+
+    if [ "$IPTABLES_IS_VALID" -eq 0 ]; then
+        ok "all listening ports have a corresponding rule in ufw"
+    fi
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    audit
+    if [ "$IPTABLES_IS_VALID" -ne 0 ]; then
+        # Debian 12 CIS marks this script as "Automated", but we wont do it
+        # How can we know if a rule should be allowed or denied ? From everywhere ? A specific range ?
+        warn "Please review the iptables rules and update them accordingly. We wont do it in an automated way, as we don't know if it should be allowed or denied"
+    fi
+
+}
+
+# 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 "$CIS_LIB_DIR" ]; then
+    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
+    echo "Cannot source CIS_LIB_DIR variable, aborting."
+    exit 128
+fi
+
+# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
+if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
+    # shellcheck source=../../lib/main.sh
+    . "${CIS_LIB_DIR}"/main.sh
+else
+    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
+    exit 128
+fi
diff --git a/tests/hardening/ip6tables_default_deny_policy.sh b/tests/hardening/ip6tables_default_deny_policy.sh
new file mode 100644
index 0000000..6fc0baa
--- /dev/null
+++ b/tests/hardening/ip6tables_default_deny_policy.sh
@@ -0,0 +1,16 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Prepare test
+    apt install -y iptables
+
+    # not much to test here, unless working on a privileged container
+    describe Running on blank host
+    register_test retvalshouldbe 1
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe clean test
+    apt remove -y iptables
+
+}
diff --git a/tests/hardening/ip6tables_loopback.sh b/tests/hardening/ip6tables_loopback.sh
new file mode 100644
index 0000000..6fc0baa
--- /dev/null
+++ b/tests/hardening/ip6tables_loopback.sh
@@ -0,0 +1,16 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Prepare test
+    apt install -y iptables
+
+    # not much to test here, unless working on a privileged container
+    describe Running on blank host
+    register_test retvalshouldbe 1
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe clean test
+    apt remove -y iptables
+
+}
diff --git a/tests/hardening/ip6tables_outbound_established.sh b/tests/hardening/ip6tables_outbound_established.sh
new file mode 100644
index 0000000..6fc0baa
--- /dev/null
+++ b/tests/hardening/ip6tables_outbound_established.sh
@@ -0,0 +1,16 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Prepare test
+    apt install -y iptables
+
+    # not much to test here, unless working on a privileged container
+    describe Running on blank host
+    register_test retvalshouldbe 1
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe clean test
+    apt remove -y iptables
+
+}
diff --git a/tests/hardening/ip6tables_rule_them_all.sh b/tests/hardening/ip6tables_rule_them_all.sh
new file mode 100644
index 0000000..6fc0baa
--- /dev/null
+++ b/tests/hardening/ip6tables_rule_them_all.sh
@@ -0,0 +1,16 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Prepare test
+    apt install -y iptables
+
+    # not much to test here, unless working on a privileged container
+    describe Running on blank host
+    register_test retvalshouldbe 1
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe clean test
+    apt remove -y iptables
+
+}
diff --git a/tests/hardening/iptables_loopback.sh b/tests/hardening/iptables_loopback.sh
new file mode 100644
index 0000000..6fc0baa
--- /dev/null
+++ b/tests/hardening/iptables_loopback.sh
@@ -0,0 +1,16 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Prepare test
+    apt install -y iptables
+
+    # not much to test here, unless working on a privileged container
+    describe Running on blank host
+    register_test retvalshouldbe 1
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe clean test
+    apt remove -y iptables
+
+}
diff --git a/tests/hardening/iptables_outbound_established.sh b/tests/hardening/iptables_outbound_established.sh
new file mode 100644
index 0000000..6fc0baa
--- /dev/null
+++ b/tests/hardening/iptables_outbound_established.sh
@@ -0,0 +1,16 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Prepare test
+    apt install -y iptables
+
+    # not much to test here, unless working on a privileged container
+    describe Running on blank host
+    register_test retvalshouldbe 1
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe clean test
+    apt remove -y iptables
+
+}
diff --git a/tests/hardening/iptables_rule_them_all.sh b/tests/hardening/iptables_rule_them_all.sh
new file mode 100644
index 0000000..6fc0baa
--- /dev/null
+++ b/tests/hardening/iptables_rule_them_all.sh
@@ -0,0 +1,16 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Prepare test
+    apt install -y iptables
+
+    # not much to test here, unless working on a privileged container
+    describe Running on blank host
+    register_test retvalshouldbe 1
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe clean test
+    apt remove -y iptables
+
+}