This change gets rid of the separate role dir and puts everything into the root-directory, making it possible to install the role via ansible galaxy.
6.3 KiB
os-hardening (Ansible Role)
Description
This roles provides numerous security-related configurations, providing all-round base protection.
It configures:
- Configures package management e.g. allows only signed packages
- Remove packages with known issues
- Configures
pam
andpam_limits
module - Shadow password suite configuration
- Configures system path permissions
- Disable core dumps via soft limits
- Restrict Root Logins to System Console
- Set SUIDs
- Configures kernel parameters via sysctl
It will not:
- Update system packages
- Install security patches
Requirements
- Ansible
Variables
in main.yml
os_desktop_enable: false
- true if this is a desktop system, ie Xorg, KDE/GNOME/Unity/etcos_env_extra_user_paths: []
- add additional paths to the user'sPATH
variable (default is empty).os_env_umask: "027"
os_auth_pw_max_age: 60
- maximum password ageos_auth_pw_min_age: 7
- minimum password age (before allowing any other password change)os_auth_retries: 5
- the maximum number of authentication attempts, before the account is locked for some timeos_auth_lockout_time: 600
- time in seconds that needs to pass, if the account was locked due to too many failed authentication attemptsos_auth_timeout: 60
- authentication timeout in seconds, so login will exit if this time passesos_auth_allow_homeless: false
- true if to allow users without home to loginos_auth_pam_passwdqc_enable: true
- true if you want to use strong password checking in PAM using passwdqcos_auth_pam_passwdqc_options: "min=disabled,disabled,16,12,8"
- set to any option line (as a string) that you want to pass to passwdqcos_security_users_allow: []
- list of things, that a user is allowed to do. May contain:change_user
os_security_kernel_enable_module_loading: true
- true if you want to allowed to change kernel modules once the system is running (egmodprobe
,rmmod
)os_security_kernel_enable_sysrq: false
os_security_kernel_enable_core_dump: false
os_security_suid_sgid_enforce: true
- true if you want to reduce SUID/SGID bits. There is already a list of items which are searched for configured, but you can also add your ownos_security_suid_sgid_blacklist: []
- a list of paths which should have their SUID/SGID bits removedos_security_suid_sgid_whitelist: []
- a list of paths which should not have their SUID/SGID bits alteredos_security_suid_sgid_remove_from_unknown: false
- true if you want to remove SUID/SGID bits from any file, that is not explicitly configured in ablacklist
. This will make every Ansible-run search through the mounted filesystems looking for SUID/SGID bits that are not configured in the default and user blacklist. If it finds an SUID/SGID bit, it will be removed, unless this file is in yourwhitelist
.os_security_packages_clean': true
- removes packages with known issues. See section packages.
in sysctl.yml
os_network_forwarding: false
- true if this system requires packet forwarding (eg Router), false otherwiseos_network_ipv6_enable: false
os_network_arp_restricted: true
- true if you want the behavior of announcing and replying to ARP to be restricted, false otherwise
Packages
We remove the following packages:
- xinetd (NSA, Chapter 3.2.1)
- inetd (NSA, Chapter 3.2.1)
- tftp-server (NSA, Chapter 3.2.5)
- ypserv (NSA, Chapter 3.2.4)
- telnet-server (NSA, Chapter 3.2.2)
- rsh-server (NSA, Chapter 3.2.3)
Example Playbook
- hosts: localhost
roles:
- hardening.os-hardening
Local Testing
For local testing you can use vagrant and Virtualbox of VMWare to run tests locally. You will have to install Virtualbox and Vagrant on your system. See Vagrant Downloads for a vagrant package suitable for your system. For all our tests we use test-kitchen
. If you are not familiar with test-kitchen
please have a look at their guide.
Next install test-kitchen:
# Install dependencies
gem install bundler
bundle install
# Fetch tests
bundle exec thor kitchen:fetch-remote-tests
# fast test on one machine
bundle exec kitchen test default-ubuntu-1204
# test on all machines
bundle exec kitchen test
# for development
bundle exec kitchen create default-ubuntu-1204
bundle exec kitchen converge default-ubuntu-1204
For more information see test-kitchen
Contributors + Kudos
...
This role is mostly based on guides by:
- Arch Linux wiki, Sysctl hardening
- NSA: Guide to the Secure Configuration of Red Hat Enterprise Linux 5
- Ubuntu Security/Features
- Deutsche Telekom, Group IT Security, Security Requirements (German)
Thanks to all of you!
Contributing
License and Author
- Author:: Sebastian Gumprich sebastian.gumprich@38.de
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.