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
2025-09-04 13:38:24 +02:00 · 2025-08-05 16:23:52 +02:00
parent 1926758707
commit 4be1a9d9e4
14 changed files with 819 additions and 0 deletions
--- a/bin/hardening/iptables_loopback.sh
+++ 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