add "apt_remove" in lib/utils.sh

in order to manage DEBIAN_FRONTEND

bin/hardening/chrony_is_enabled_and_running.sh

@@ -0,0 +1,91 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure chrony is enabled and running (Automated)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=3
+# shellcheck disable=2034
+DESCRIPTION="Ensure chrony is enabled and running."
+PACKAGE="chrony"
+SERVICE="chrony"
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    CHRONY_INSTALLED=0
+    CHRONY_ENABLED=0
+    CHRONY_RUNNING=0
+
+    is_pkg_installed "$PACKAGE"
+    if [ "$FNRET" -ne 0 ]; then
+        CHRONY_INSTALLED=1
+        crit "chrony is not installed"
+    fi
+    # no package, no need to check further
+    return
+
+    is_service_enabled "$SERVICE"
+    if [ "$FNRET" -ne 0 ]; then
+        CHRONY_INSTALLED=1
+        crit "chrony is not enabled"
+    fi
+
+    is_service_active "$SERVICE"
+    if [ "$FNRET" -ne 0 ]; then
+        CHRONY_RUNNING=1
+        crit "chrony is not running"
+    fi
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    audit
+    if [ "$CHRONY_INSTALLED" -eq 1 ]; then
+        warn "Please install chrony manually to ensure only one time synchronization system is installed"
+    fi
+
+    if [ "$CHRONY_ENABLED" -eq 1 ]; then
+        info "Enablign chrony service"
+        manage_service "enable" "$SERVICE"
+    fi
+
+    if [ "$CHRONY_RUNNING" -eq 1 ]; then
+        info "Starting chrony service"
+        manage_service "start" "$SERVICE"
+    fi
+
+}
+
+# This function will check config parameters required
+check_config() {
+    :
+}
+
+# Source Root Dir Parameter
+if [ -r /etc/default/cis-hardening ]; then
+    # shellcheck source=../../debian/default
+    . /etc/default/cis-hardening
+fi
+if [ -z "$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

bin/hardening/network_services_listening.sh

@@ -0,0 +1,84 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure only approved services are listening on a network interface (Manual)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=3
+# shellcheck disable=2034
+DESCRIPTION="Ensure only approved services are listening on a network interface"
+# socket
+# ex: "127.0.0.1:123 0.0.0.0:123"
+# we only care about the socket, as there may be different process for a same service
+# ex: ntp or chrony for time synchronization
+EXCEPTIONS=""
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    local is_valid=0
+    while read i; do
+        socket=$(echo "$i" | awk '{print $5}')
+        proc=$(echo "$i" | awk '{print $7}' | awk -F ',' '{print $1}' | sed 's/users:((//')
+        [ -n "$socket" ] && info -e "$proc listening on \t$socket"
+
+        # output example :
+        # "ntpd" listening on 	127.0.0.1:123
+        # "ntpd" listening on 	0.0.0.0:123
+
+        if grep -w "$socket" <<<"$EXCEPTIONS" >/dev/null; then
+            debug "$socket" is an exception
+        else
+            crit "$socket" is not an exception
+        fi
+
+    done <<<"$($SUDO_CMD ss -plntuH)"
+
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    info "This recommendation has to be reviewed and applied manually"
+}
+
+create_config() {
+    # we try to put as default all services that should be running according to the CIS recommendation
+    cat <<EOF
+status=audit
+# Put your custom configuration here
+EXCEPTIONS="127.0.0.1:123 0.0.0.0:123 0.0.0.0:22"
+EOF
+}
+
+# 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

bin/hardening/tftp_is_disabled.sh

@@ -0,0 +1,91 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# Ensure tftp services are not in use (Automated)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=3
+# shellcheck disable=2034
+DESCRIPTION="Ensure tftp services are not in use."
+PACKAGE='tftpd-hpa'
+SERVICE="tftpd-hpa.service"
+
+# 2 scenario here:
+# - tftp is a dependency for another package -> disable the service
+# - tftp is not a dependency for another package -> remove the package
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    # 0 means true in bash
+    PACKAGE_INSTALLED=1
+    PACKAGE_IS_DEPENDENCY=1
+    SERVICE_ENABLED=1
+
+    is_pkg_installed "$PACKAGE"
+    [ "$FNRET" = 0 ] && PACKAGE_INSTALLED=0 # 0 means true in bash
+
+    is_pkg_a_dependency "$PACKAGE"
+    # dnsmasq is installed with dnsmasq-base, which
+    [ "$FNRET" = 0 ] && PACKAGE_IS_DEPENDENCY=0
+
+    is_service_enabled "$SERVICE"
+    [ "$FNRET" = 0 ] && SERVICE_ENABLED=0
+
+    if [ "$PACKAGE_INSTALLED" -eq 0 ] && [ "$PACKAGE_IS_DEPENDENCY" -eq 1 ]; then
+        crit "$PACKAGE is installed and not a dependency"
+    elif [ "$PACKAGE_INSTALLED" -eq 0 ] && [ "$PACKAGE_IS_DEPENDENCY" -eq 0 ] && [ "$SERVICE_ENABLED" -eq 0 ]; then
+        crit "$SERVICE is enabled"
+    else
+        ok "$PACKAGE is not in use"
+    fi
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    audit
+    if [ "$PACKAGE_INSTALLED" -eq 0 ] && [ "$PACKAGE_IS_DEPENDENCY" -eq 1 ]; then
+        crit "$PACKAGE is installed and not a dependency, removing it"
+        apt_remove "$PACKAGE" -y
+        apt-get autoremove -y
+    elif [ "$PACKAGE_INSTALLED" -eq 0 ] && [ "$PACKAGE_IS_DEPENDENCY" -eq 0 ] && [ "$SERVICE_ENABLED" -eq 0 ] && [ "$IS_CONTAINER" -eq 1 ]; then
+        crit "$SERVICE is enabled, i'm going to stop and mask it"
+        systemctl stop "$SERVICE"
+        systemctl mask "$SERVICE"
+    else
+        ok "$PACKAGE is not in use"
+    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

bin/hardening/use_time_sync.sh

@@ -6,7 +6,7 @@
 #
 
 #
-# Ensure time synchronization is in use (Not Scored)
+# Ensure a single time synchronization daemon is in use (Automated)
 #
 
 set -e # One error, it's over
@@ -15,28 +15,31 @@ set -u # One variable unset, it's over
 # shellcheck disable=2034
 HARDENING_LEVEL=3
 # shellcheck disable=2034
-DESCRIPTION="Ensure time synchronization is in use"
+DESCRIPTION="Ensure a single time synchronization is in use"
 
 PACKAGES="systemd-timesyncd ntp chrony"
 
 # This function will be called if the script status is on enabled / audit mode
 audit() {
-    FOUND=false
+    local count=0
     for PACKAGE in $PACKAGES; do
         is_pkg_installed "$PACKAGE"
-        if [ "$FNRET" = 0 ]; then
-            ok "Time synchronization is available through $PACKAGE"
-            FOUND=true
+        if [ "$FNRET" -eq 0 ]; then
+            let count=$((count + 1))
         fi
     done
-    if [ "$FOUND" = false ]; then
+    if [ "$count" -eq 0 ]; then
         crit "None of the following time sync packages are installed: $PACKAGES"
+    elif [ "$count" -gt 1 ]; then
+        crit "Multiple time sync packages are installed, from $PACKAGES. Pick one and remove the others"
+    else
+        info "A single time sync package from $PACKAGES is installed"
     fi
 }
 
 # This function will be called if the script status is on enabled mode
 apply() {
-    :
+    info "This recommendation has to be reviewed and applied manually"
 }
 
 # This function will check config parameters required

cisharden.sudoers

@@ -24,6 +24,7 @@ Cmnd_Alias SCL_CMD =    /bin/grep ,\
                         /sbin/lsmod,\
                         /sbin/modprobe,\
                         /usr/sbin/modprobe -n -v*,\
-                        /usr/sbin/apparmor_status
+                        /usr/sbin/apparmor_status,\
+                        /usr/bin/ss *
 
 cisharden ALL = (root) NOPASSWD: SCL_CMD

debian/control

@@ -10,7 +10,7 @@ Vcs-Browser: https://github.com/ovh/debian-cis/
 
 Package: cis-hardening
 Architecture: all
-Depends: ${misc:Depends}, patch, coreutils
+Depends: ${misc:Depends}, patch, coreutils, iproute2
 Description: Suite of configurable scripts to audit or harden a Debian.
  Modular Debian security hardening scripts based on cisecurity.org
  ⟨cisecurity.org⟩ recommendations. We use it at OVH ⟨https://www.ovh.com⟩ to

lib/utils.sh

@@ -575,6 +575,12 @@ apt_install() {
     FNRET=0
 }
 
+apt_remove() {
+    local PACKAGE=$1
+    DEBIAN_FRONTEND='noninteractive' apt remove -y "$PACKAGE"
+    FNRET=0
+}
+
 #
 #   Returns if a package is installed
 #

tests/docker/Dockerfile.debian11

@@ -7,7 +7,7 @@ LABEL description="This image is used to run tests"
 
 RUN groupadd -g 500 secaudit && useradd  -u 500 -g 500 -s /bin/bash secaudit && install -m 700 -o secaudit -g secaudit -d /home/secaudit
 
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y openssh-server sudo syslog-ng net-tools auditd cron
+RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y openssh-server sudo syslog-ng net-tools auditd cron iproute2
 
 COPY --chown=500:500 . /opt/debian-cis/
 

tests/docker/Dockerfile.debian12

@@ -7,7 +7,7 @@ LABEL description="This image is used to run tests"
 
 RUN groupadd -g 500 secaudit && useradd  -u 500 -g 500 -s /bin/bash secaudit && install -m 700 -o secaudit -g secaudit -d /home/secaudit
 
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y openssh-server sudo syslog-ng net-tools auditd cron
+RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y openssh-server sudo syslog-ng net-tools auditd cron iproute2
 
 COPY --chown=500:500 . /opt/debian-cis/
 

tests/hardening/chrony_is_enabled_and_running.sh

@@ -0,0 +1,18 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+
+    describe Ensure package is installed
+
+    # install dependencies
+    apt update
+    apt install -y chrony
+
+    # not much to test here, we are running in a container, we wont check service state
+    describe Checking blank host
+    register_test retvalshouldbe 0
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    apt remove -y chrony
+
+}

tests/hardening/network_services_listening.sh

@@ -0,0 +1,33 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Prepare exceptions tests
+    apt install -y netcat-traditional
+    timeout 5s nc -lp 123 | true &
+
+    describe Running succesfull check
+    register_test retvalshouldbe 0
+    # shellcheck disable=2154
+    run success "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe Prepare on purpose failing tests
+    timeout 5s nc -lp 80 | true &
+
+    describe Running failed check
+    register_test retvalshouldbe 1
+    # shellcheck disable=2154
+    run failed "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe correcting situation
+    # just wait for timeout to expire
+    sleep 5
+
+    describe Checking resolved state
+    register_test retvalshouldbe 0
+    run resolved "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe clean installation
+    apt remove -y netcat-traditional
+    apt autoremove -y
+
+}

tests/hardening/tftp_is_disabled.sh

@@ -0,0 +1,36 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+
+    describe Prepare on purpose failed test
+    apt install -y tftpd-hpa
+    # running on a container, will can only test the package installation, not the service management
+
+    describe Running on purpose failed test
+    register_test retvalshouldbe 1
+    # shellcheck disable=2154
+    run failed "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe correcting situation
+    sed -i 's/audit/enabled/' "${CIS_CONF_DIR}/conf.d/${script}.cfg"
+    "${CIS_CHECKS_DIR}/${script}.sh" --apply || true
+
+    describe Checking resolved state
+    register_test retvalshouldbe 0
+    run resolved "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe Prepare test package dependencies
+    # try to install a package that depends on 'tftpd-hpa'
+    apt install -y tftp-hpa-dbg
+    # running on a container, we can only test the package installation, not the service management
+
+    describe Running successfull test
+    register_test retvalshouldbe 0
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    describe clean installation
+    apt remove -y tftp-hpa-dbg tftpd-hpa
+    apt autoremove -y
+
+}

tests/hardening/use_time_sync.sh

@@ -3,7 +3,6 @@
 test_audit() {
     describe Running on blank host
     register_test retvalshouldbe 1
-    dismiss_count_for_test
     # shellcheck disable=2154
     run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
 
@@ -14,6 +13,11 @@ test_audit() {
     # Finally assess that your corrective actions end up with a compliant system
     describe Checking resolved state
     register_test retvalshouldbe 0
-    register_test contain "Time synchronization is available through"
     run resolved "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    # we can not check the presence of multiple time synchronization from debian packages, as they are mutually exclusive
+    describe clean installation
+    apt remove -y ntp
+    apt autoremove -y
+
 }