harbian-audit Hardening

Introduction

Hardened Debian GNU/Linux distro auditing.

The main test environment is in debian 9, and other versions are not fully tested. There are no implementations of SELinux related items in this release.

The code framework is based on the OVH-debian-cis project, Modified some of the original implementations according to the features of Debian 9, added and implemented check items for STIG V1R4 and cisecurity.org recommendations, and also added and implemented some check items by the HardenedLinux community. The audit and apply functions of the infrastructure are implemented, and the automatic fix function is implemented for the items that can be automatically fixed.

# bash bin/hardening.sh --audit-all
[...]
hardening                 [INFO] Treating /home/test/harbian-audit/bin/hardening/13.15_check_duplicate_gid.sh
13.15_check_duplicate_gid [INFO] Working on 13.15_check_duplicate_gid
13.15_check_duplicate_gid [INFO] Checking Configuration
13.15_check_duplicate_gid [INFO] Performing audit
13.15_check_duplicate_gid [ OK ] No duplicate GIDs
13.15_check_duplicate_gid [ OK ] Check Passed

[...]
################### SUMMARY ###################
      Total Available Checks : 256
         Total Runned Checks : 256
         Total Passed Checks : [ 111/256 ]
         Total Failed Checks : [ 144/256 ]
   Enabled Checks Percentage : 100.00 %
       Conformity Percentage : 43.36 %

Quickstart

$ git clone https://github.com/hardenedlinux/harbian-audit.git && cd harbian-audit
# cp debian/default /etc/default/cis-hardening
# sed -i "s#CIS_ROOT_DIR=.*#CIS_ROOT_DIR='$(pwd)'#" /etc/default/cis-hardening
# bin/hardening/1.1_install_updates.sh --audit-all
1.1_install_updates       [INFO] Working on 1.1_install_updates
1.1_install_updates       [INFO] Checking Configuration
1.1_install_updates       [INFO] Performing audit
1.1_install_updates       [INFO] Checking if apt needs an update
1.1_install_updates       [INFO] Fetching upgrades ...
1.1_install_updates       [ OK ] No upgrades available
1.1_install_updates       [ OK ] Check Passed

Usage

Pre-Install

If use Network install from a minimal CD to installed Debian GNU/Linux, need install bc package before use the hardening tool.

# apt-get install -y bc net-tools 

Configuration

Hardening scripts are in bin/hardening. Each script has a corresponding configuration file in etc/conf.d/[script_name].cfg.

Each hardening script can be individually enabled from its configuration file. For example, this is the default configuration file for disable_system_accounts:

# Configuration for script of same name
status=disabled
# Put here your exceptions concerning admin accounts shells separated by spaces
EXCEPTIONS=""

status parameter may take 3 values:

• disabled (do nothing): The script will not run.
• audit (RO): The script will check if any change should be applied.
• enabled (RW): The script will check if any change should be done and automatically apply what it can.

You can also set the configuration item to enable by modifying the level, following command:

1. Generate etc/conf.d/[script_name].cfg by audit-all when first use

# bash bin/hardening.sh --audit-all

2. Enable [script_name].cfg by set-hardening-level Use the command to set the hardening level to make the corresponding level audit entry take effect.

# bash bin/hardening.sh --set-hardening-level <level>

Global configuration is in etc/hardening.cfg. This file controls the log level as well as the backup directory. Whenever a script is instructed to edit a file, it will create a timestamped backup in this directory.

Run aka "Harden your distro"

To run the checks and apply the fixes, run bin/hardening.sh.

This command has 2 main operation modes:

• --audit: Audit your system with all enabled and audit mode scripts
• --apply: Audit your system with all enabled and audit mode scripts and apply changes for enabled scripts

Additionally, --audit-all can be used to force running all auditing scripts, including disabled ones. this will not change the system.

--audit-all-enable-passed can be used as a quick way to kickstart your configuration. It will run all scripts in audit mode. If a script passes, it will automatically be enabled for future runs. Do NOT use this option if you have already started to customize your configuration.

After remediation

When exec --apply and set-hardening-level are set to 5 (the highest level), you need to do the following:

1. When applying 9.5(Restrict Access to the su Command), you must use the root account to log in to the OS because ordinary users cannot perform subsequent operations.

2. When applying 7.4.4_hosts_deny.sh, the OS cannot be connected through the ssh service, so you need to set allow access host list on /etc/hosts.allow, example:

# echo "ALL: 192.168.1. 192.168.5." >> /etc/hosts.allow

3. Set capabilities for usual user, example(user name is test):

# sed -i "/^root/a\test    ALL=(ALL:ALL) ALL" /etc/sudoers 

4. Set basic iptables rules Set the corresponding firewall rules according to the applications used. HardenedLinux community for Debian GNU/Linux firewall rules: etc.iptables.rules.v4.sh

5. Use the passwd command to change the passwords of all users, and change the password to a secure and reliable password entry with the same password complexity set by the pam_cracklib module.

Hacking

Getting the source

$ git clone https://github.com/hardenedlinux/harbian-audit.git

Adding a custom hardening script

$ cp src/skel bin/hardening/99.99_custom_script.sh
$ chmod +x bin/hardening/99.99_custom_script.sh
$ cp src/skel.cfg etc/conf.d/99.99_custom_script.cfg

Code your check explaining what it does then if you want to test

$ sed -i "s/status=.+/status=enabled/" etc/conf.d/99.99_custom_script.cfg
$ bash bin/hardening.sh --audit --only 99.99
$ bash bin/hardening.sh --apply --only 99.99

Document

Harbian-audit benchmark for Debian GNU/Linux 9

This document is a description of the additions to the sections not included in the CIS reference documentation. Includes STIG reference documentation and additional checks recommended by the HardenedLinux community.
harbian audit Debian Linux 9 Benchmark

Manual Operation docs

How to config grub2 password protection

harbian-audit License

GPL 3.0

OVH Disclaimer

This project is a set of tools. They are meant to help the system administrator built a secure environment. While we use it at OVH to harden our PCI-DSS compliant infrastructure, we can not guarantee that it will work for you. It will not magically secure any random host.

Additionally, quoting the License:

THIS SOFTWARE IS PROVIDED BY OVH SAS AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL OVH SAS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

OVH License

3-Clause BSD

Reference

• Center for Internet Security: https://www.cisecurity.org/
• STIG V1R4: https://iasecontent.disa.mil/stigs/zip/U_Red_Hat_Enterprise_Linux_7_V1R4_STIG.zip
• Firewall Rules: https://github.com/citypw/arsenal-4-sec-testing/blob/master/bt5_firewall/debian_fw