Security Hardening for Hosts


2015-09-10 00:00



The goal of this spec is to apply hardening standards to openstack-ansible so that users can build environments that meet the requirements of various compliance programs, such as the Payment Card Industry Data Security Standard (PCI-DSS). These changes won’t make a particular environment PCI compliant, but they should bring the environment in compliance with Requirement 2.2 from PCI-DSS. That requirement states that deployments must follow an industry-accepted hardening standard.

Blueprint - Security Hardening for OSAD Hosts:

Problem description

Compliance programs, such as PCI-DSS, often have a requirement for using industry-accepted hardening standards for all deployments. At the moment, deployments done on Ubuntu 14.04 with openstack-ansible meet many, but not all, security hardening standards that are approved within PCI-DSS.

PCI-DSS 3.1 Requirement 2.2 states that deployments that handle credit card data must be secured with industry-accepted hardening standards. The test of the requirement is as follows:

2.2 Develop configuration standards for all system components. Assure that these standards address all known security vulnerabilities and are consistent with industry-accepted system hardening standards.

The United States Defense Information Systems Agency (DISA) publishes sets of security hardening guides called Security Technical Implementation Guides (STIGs). They’re comprehensive and they provide mechanisms for checking secured systems for compliance with the standards. In addition, they are in the public domain.

Proposed change

The proposed changes include:

  1. Create a new role in a new repo to hold the security tasks

    • See Work items below for specifics about the role.

  2. Write documentation about the hardening standards applied

    • Is this standard already deployed by default in Ubuntu 14.04 or by OSAD already?

    • If a standard is applied, what does a deployer gain from it?

    • If a standard is skipped, why was it skipped and what does the deployer lose?

  3. Submit patches that actually apply those hardening standards

    • Start by making a bug for each with a description of what will be changed and why

    • Determine whether the patch belongs in openstack-ansible or within a new security-hardening role that can be pulled into openstack-ansible during deployments

  4. Create an automated way to test that the security changes are applied and they don’t cause negative impacts on openstack-ansible deployments

    • This could be done via OpenSCAP or via CIS’ Java-based checker

    • Needs to be checked via gate check jobs

  5. Make it easy for deployers to import the security hardening role into openstack-ansible

    • Should be easily pulled into an openstack-ansible deployment if a deployer chooses

Here are several examples of security improvements recommended by the RHEL 6 STIG which apply well to Ubuntu:

  • V-38497: The system must not have accounts configured with blank or null passwords.

  • V-38476: Vendor-provided cryptographic certificates must be installed to verify the integrity of system software.

  • V-38607: The SSH daemon must be configured to use only the SSHv2 protocol.

  • V-38614: The SSH daemon must not allow authentication using an empty password.

  • V-38673: The operating system must ensure unauthorized, security-relevant configuration changes detected are tracked.

  • V-38632: The operating system must produce audit records containing sufficient information to establish what type of events occurred.


No known alternatives.

Playbook/Role impact

Depending on the nature of the change and the usefulness to deployers, the changes may be applied directly to existing roles in openstack-ansible or they may be applied to security hardening role that is optionally pulled in during openstack-ansible deployments

Any changes which could affect the performance, stability, or functionality of a production deployment would be disabled by default and heavily documented. Deployers could then make an educated decision on whether or not they want that security hardening standard enabled.

Upgrade impact

If security features are added via feature flags and disabled by default, the effect on upgrades would be very minimal if they’re even noticed at all. All configuration changes should be examined individually to determine if they will have an impact on upgrades.

Security impact

The entire goal of this spec is to have a positive security impact without becoming an operational burden.

Performance impact

It’s possible that some security changes could impact the performance of a running OpenStack system. As noted in Upgrade impact above, these configuration changes would need to be examined individually to determine the balance between security and performance impacts.

End user impact

End users shouldn’t notice the majority of the security changes. They will still interact with API endpoints and virtual machines as they do today. There’s a chance that some security improvements could impact an end user, but deployers will have full control of how those improvements are applied.

Deployer impact

Deployers could potentially be able to build OpenStack systems that are more secure by default. However, if these security features are disabled by default, we need solid documentation that tells users how to enable these features and what the impact of enabling those features might be.

Deployers would need to explicitly include the security hardening role within their openstack-ansible deployments.

Developer impact

Developers would need to include the security hardening role within their deployments if they wanted to test openstack-ansible with additional security enhancements.


This spec has no dependencies.



Who is leading the writing of the code? Or is this a blueprint where you’re throwing it out there to see who picks it up?

If more than one person is working on the implementation, please designate the primary author and contact.

Primary assignee:

Major Hayden (LP: rackerhacker, IRC: mhayden)

Other contributors:

Cody Bunch (LP: cody-bunch, IRC: e-vad)

Work items

The security hardening role should be in a separate repository titled openstack-ansible-security. Once the role has content and is well-tested against openstack-ansible, it could be added as an optional dependency within openstack-ansible. Documentation for the new role could be added into the existing openstack-ansible documentation to make it easier for openstack-ansible users to reference it.

The other work items are in the Proposed change section above in a numbered list. Each configuration change should come with documentation about the change.


The usual gate checks can be used for these changes. Also, each individual commit can be tested individually.

Documentation impact

Documentation is a critical piece of this spec, and it’s the first step in the process. It would be helpful to get the documentation team to weigh in on some of the documentation changes to ensure it makes sense for deployers.


Mailing list thread:

IRC discussion: