mirror of
https://github.com/ovh/debian-cis.git
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4be1a9d9e4
- 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
103 lines
3.3 KiB
Bash
Executable File
103 lines
3.3 KiB
Bash
Executable File
#!/bin/bash
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# run-shellcheck
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#
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# CIS Debian Hardening
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#
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#
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# Ensure iptables firewall rules exist for all open ports (Manual)
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#
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set -e # One error, it's over
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set -u # One variable unset, it's over
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# shellcheck disable=2034
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HARDENING_LEVEL=2
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# shellcheck disable=2034
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DESCRIPTION="Ensure iptables firewall rules exist for all open ports"
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PACKAGE="iptables"
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# we are going to
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# - list listening ports
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# - list iptables rules using dport
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# - compare both
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# This function will be called if the script status is on enabled / audit mode
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audit() {
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is_pkg_installed "$PACKAGE"
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if [ "$FNRET" -ne 0 ]; then
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crit "$PACKAGE is not installed"
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return
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fi
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IPTABLES_IS_VALID=0
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local iptables_ports_rules=""
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local listening_ports
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# we may have configured some custom chains in INPUT, that need to be checked too.
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local custom_chains=""
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local builtin_targets="ACCEPT DROP QUEUE RETURN"
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for target in $($SUDO_CMD iptables -L INPUT | awk '{print $1}' | sed '1,2d'); do
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if ! grep "$target" <<<"$builtin_targets" >/dev/null; then
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custom_chains="$custom_chains $target"
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fi
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done
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for chain in INPUT $custom_chains; do
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# number of fields is not fixed, there may be some comments before and after
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# ex:
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# udp spt:68 dpt:67 /* DHCP Request */
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# /* ssh connection */ tcp dpt:22
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iptables_ports_rules="$iptables_ports_rules $($SUDO_CMD iptables -nL "$chain" | grep 'dpt:' | sed 's/^.*dpt://g' | awk '{print $1}' | sort -u)"
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done
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listening_ports=$($SUDO_CMD ss -tuln | awk '($5!~/%lo:/ && $5!~/127.0.0.1:/ && $5!~/\[?::1\]?:/) {split($5, a, ":"); print a[2]}' | sort -u)
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for port in $listening_ports; do
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if ! grep "$port" <<<"$iptables_ports_rules" >/dev/null; then
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crit "$port does not have an iptables rule"
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IPTABLES_IS_VALID=1
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fi
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done
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if [ "$IPTABLES_IS_VALID" -eq 0 ]; then
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ok "all listening ports have a corresponding rule in ufw"
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fi
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}
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# This function will be called if the script status is on enabled mode
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apply() {
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audit
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if [ "$IPTABLES_IS_VALID" -ne 0 ]; then
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# Debian 12 CIS marks this script as "Automated", but we wont do it
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# How can we know if a rule should be allowed or denied ? From everywhere ? A specific range ?
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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"
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fi
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}
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# This function will check config parameters required
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check_config() {
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:
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}
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# Source Root Dir Parameter
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if [ -r /etc/default/cis-hardening ]; then
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# shellcheck source=../../debian/default
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. /etc/default/cis-hardening
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fi
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if [ -z "$CIS_LIB_DIR" ]; then
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echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
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echo "Cannot source CIS_LIB_DIR variable, aborting."
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exit 128
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fi
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# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
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if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
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# shellcheck source=../../lib/main.sh
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. "${CIS_LIB_DIR}"/main.sh
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else
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echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
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exit 128
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fi
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