mirror of
https://github.com/ovh/debian-cis.git
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184 lines
7.1 KiB
Markdown
184 lines
7.1 KiB
Markdown
# CIS Debian 7/8/9 Hardening
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Modular Debian 7/8/9 security hardening scripts based on [cisecurity.org](https://www.cisecurity.org)
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recommendations. We use it at [OVH](https://www.ovh.com) to harden our PCI-DSS infrastructure.
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```console
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$ bin/hardening.sh --audit-all
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[...]
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hardening [INFO] Treating /opt/cis-hardening/bin/hardening/13.15_check_duplicate_gid.sh
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13.15_check_duplicate_gid [INFO] Working on 13.15_check_duplicate_gid
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13.15_check_duplicate_gid [INFO] Checking Configuration
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13.15_check_duplicate_gid [INFO] Performing audit
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13.15_check_duplicate_gid [ OK ] No duplicate GIDs
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13.15_check_duplicate_gid [ OK ] Check Passed
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[...]
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################### SUMMARY ###################
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Total Available Checks : 191
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Total Runned Checks : 191
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Total Passed Checks : [ 170/191 ]
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Total Failed Checks : [ 21/191 ]
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Enabled Checks Percentage : 100.00 %
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Conformity Percentage : 89.01 %
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```
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## Quickstart
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```console
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$ git clone https://github.com/ovh/debian-cis.git && cd debian-cis
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$ cp debian/default /etc/default/cis-hardening
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$ sed -i "s#CIS_ROOT_DIR=.*#CIS_ROOT_DIR='$(pwd)'#" /etc/default/cis-hardening
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$ bin/hardening/1.1_install_updates.sh --audit-all
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1.1_install_updates [INFO] Working on 1.1_install_updates
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1.1_install_updates [INFO] Checking Configuration
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1.1_install_updates [INFO] Performing audit
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1.1_install_updates [INFO] Checking if apt needs an update
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1.1_install_updates [INFO] Fetching upgrades ...
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1.1_install_updates [ OK ] No upgrades available
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1.1_install_updates [ OK ] Check Passed
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```
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## Usage
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### Configuration
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Hardening scripts are in ``bin/hardening``. Each script has a corresponding
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configuration file in ``etc/conf.d/[script_name].cfg``.
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Each hardening script can be individually enabled from its configuration file.
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For example, this is the default configuration file for ``disable_system_accounts``:
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```
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# Configuration for script of same name
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status=disabled
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# Put here your exceptions concerning admin accounts shells separated by spaces
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EXCEPTIONS=""
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```
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``status`` parameter may take 3 values:
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- ``disabled`` (do nothing): The script will not run.
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- ``audit`` (RO): The script will check if any change *should* be applied.
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- ``enabled`` (RW): The script will check if any change should be done and automatically apply what it can.
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Global configuration is in ``etc/hardening.cfg``. This file controls the log level
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as well as the backup directory. Whenever a script is instructed to edit a file, it
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will create a timestamped backup in this directory.
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### Run aka "Harden your distro"
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To run the checks and apply the fixes, run ``bin/hardening.sh``.
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This command has 2 main operation modes:
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- ``--audit``: Audit your system with all enabled and audit mode scripts
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- ``--apply``: Audit your system with all enabled and audit mode scripts and apply changes for enabled scripts
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Additionally, ``--audit-all`` can be used to force running all auditing scripts,
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including disabled ones. this will *not* change the system.
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``--audit-all-enable-passed`` can be used as a quick way to kickstart your
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configuration. It will run all scripts in audit mode. If a script passes,
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it will automatically be enabled for future runs. Do NOT use this option
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if you have already started to customize your configuration.
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``--sudo``: Audit your system as a normal user, but allow sudo escalation to read
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specific root read-only files. You need to provide a sudoers file in /etc/sudoers.d/
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with NOPASWD option, since checks are executed with ``sudo -n`` option, that will
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not prompt for a password.
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``--batch``: While performing system audit, this option sets LOGLEVEL to 'ok' and
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captures all output to print only one line once the check is done, formatted like :
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OK|KO OK|KO|WARN{subcheck results} [OK|KO|WARN{...}]
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## Hacking
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**Getting the source**
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```console
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$ git clone https://github.com/ovh/debian-cis.git
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```
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**Building a debian Package** (the hacky way)
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```console
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$ debuild -us -uc
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```
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**Adding a custom hardening script**
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```console
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$ cp src/skel bin/hardening/99.99_custom_script.sh
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$ chmod +x bin/hardening/99.99_custom_script.sh
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$ cp src/skel.cfg etc/conf.d/99.99_custom_script.cfg
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```
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Code your check explaining what it does then if you want to test
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```console
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$ sed -i "s/status=.+/status=enabled/" etc/conf.d/99.99_custom_script.cfg
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$ ./bin/hardening/99.99_custom_script.sh
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```
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## Functional testing
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Functional tests are available. They are to be run in a Docker environment.
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```console
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$ ./tests/docker_build_and_run_tests.sh <target> [name of test script...]
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```
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With `target` being like `debian8` or `debian9`.
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Running without script arguments will run all tests in `./tests/hardening/` directory.
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Or you can specify one or several test script to be run.
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This will build a new Docker image from the current state of the projet and run
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a container that will assess a blank Debian system compliance for each check.
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For hardening audit points the audit is expected to fail, then be fixed so that
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running the audit a second time will succeed.
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For vulnerable items, the audit is expected to succeed on a blank
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system, then the functional tests will introduce a weak point, that is expected
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to be detected when running the audit test a second time. Finally running the `apply`
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part of debian-cis script will restore a compliance state that is expected to be
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assed by running the audit check a third time.
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Functional tests can make use of the following helper functions :
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* `describe <test description>`
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* `run <usecase> <audit_script> <audit_script_options>`
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* `register_test <test content (see below)>`
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* `retvalshoudbe <integer>` check the script return value
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* `contain "<SAMPLE TEXT>"` check that the output contains the following text
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In order to write your own functional test, you will find a code skeleton in
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`./src/skel.test`.
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## Disclaimer
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This project is a set of tools. They are meant to help the system administrator
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built a secure environment. While we use it at OVH to harden our PCI-DSS compliant
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infrastructure, we can not guarantee that it will work for you. It will not
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magically secure any random host.
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Additionally, quoting the License:
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> THIS SOFTWARE IS PROVIDED BY OVH SAS AND CONTRIBUTORS ``AS IS'' AND ANY
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> EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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> WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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> DISCLAIMED. IN NO EVENT SHALL OVH SAS AND CONTRIBUTORS BE LIABLE FOR ANY
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> DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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> (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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> LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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> ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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> (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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> SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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## Reference
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- **Center for Internet Security**: https://www.cisecurity.org/
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- **CIS recommendations**: https://benchmarks.cisecurity.org/downloads/show-single/index.cfm?file=debian7.100
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- **CIS recommendations**: https://benchmarks.cisecurity.org/downloads/show-single/index.cfm?file=debian8.100
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## License
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3-Clause BSD
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