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Vulnerability Management

Revision as of 15:13, 20 November 2014 by Tristan Cacqueray (talk | contribs) (Incident report taxonomy: remove weird whitespace...)

The OpenStack vulnerability management team (VMT) is responsible for coordinating the progressive disclosure of a vulnerability.

Members of the team are independent and security-minded folks who ensure that vulnerabilities are dealt with in a timely manner and that downstream stakeholders are notified in a coordinated and fair manner. Where a member of the team is employed by a downstream stakeholder, the member does not give their employer prior notice of any vulnerabilities. In order to reduce the disclosure of vulnerability in the early stages, membership of this team is intentionally limited to a small number of people.

Supported versions

The Vulnerability Management team coordinates patches fixing vulnerabilities in one or two previous releases of OpenStack, in addition to the master branch (next version under development), for all security supported projects.


Each security bug is assigned a VMT coordinator (member from the vulnerability management team) that will drive the fixing and disclosure process. Here are the steps we follow.



A report can be received either as a private encrypted email to one of the VMT members, or as a Launchpad security bug (check the box marked "this is a security issue").

The first steps are to confirm the sanity of the report, create a Launchpad bug if necessary, add an ossa bugtask and subscribe the project PTL for confirmation of impact and determination of affected branches. Once we confirmed that we would issue an OSSA for it, switch the ossa bugtask status to Confirmed. If the need for an OSSA is challenged, the ossa bugtask status should be set to Incomplete until that question is resolved.

Patch development

The reporter, or the PTL, or any person that the PTL deems necessary to develop the fix is added to the security bug subscription list. A fix is proposed as a patch to the current master branch (as well as any affected supported branches) and attached to the bug.

Patch review

Once the initial patch has been posted, core developers of the project are added to the bug subscription list so that the proposed patch can be pre-approved for merging. Patches need to be pre-approved so that they can be fast-tracked through review at disclosure time.

Draft impact description

In the mean time, the VMT coordinator prepares a vulnerability description that will be communicated to downstream stakeholders, and will serve as the basis for the Security Advisory that will be finally published.

The description should properly credit the reporter, specify affected versions (including unsupported ones) and accurately describe impact and mitigation mechanisms. The VMT coordinator should use the template below. Once the description is posted, the ossa bugtask status should be switched to Triaged.

Review impact description

The description is validated by the reporter and the PTL.

CVE assignment

To ensure full traceability, we get a CVE assigned before the issue is communicated to a larger public. This is generally done as the patch gets nearer to final approval. The ossa bugtask status is set to In progress and the approved description is sent to a CNA in an encrypted+signed email in order to get a CVE assigned. If the issue is already public, the CVE request should be sent to the oss-security list instead, including links to public bugs.

Get assigned CVE

The CNA returns the assigned CVE. It is added to the Launchpad bug (see "link to CVE" at the top-right), and the bug is retitled to "$TITLE ($CVE)".

Embargoed disclosure

Once the patches are approved and the CVE is assigned, a signed email with the vulnerability description is sent to the downstream stakeholders. The disclosure date is set to 3-5 business days, excluding Monday/Friday and holiday periods, at 1500 UTC. No stakeholder is supposed to deploy public patches before disclosure date.

Once the email is sent, the ossa bugtask status should be set to Fix committed. At that point we can also add downstream stakeholders to the Launchpad bug, if they use Launchpad for security patches. This means adding ~canonical-security to the bug subscribers.

For non-embargoed, public vulnerabilities no separate downstream advance notification is sent. Instead the OSSA bugtask is set to fix committed status once the CVE assignment is received OSSA is drafting begins immediately.

Open bug, push patches

In preparation for this, make sure you have a core developer and a stable maintainer available to help pushing the fix at disclosure time.

On the disclosure hour, push patches to Gerrit for review on master and supported stable branches, open bug, fast-track approvals (referencing the bug).

Publish OSSA

Shortly after pushing the patches (potentially waiting for the first test runs to complete), publish the advisory to the OpenStack ML. Wait until all patches merged to supported branches before setting the ossa bugtask status to Fix released.

Incident report taxonomy

The VMT is now using this classification list in order to assist vulnerability report triage, especially whenever a bug does not warrant an advisory.

Classes Outcome Description
Class A OSSA A vulnerability fixed in master and all supported releases.
Class B1 OSSN Only master can be fixed, security note for stable branches, e.g., default config value is insecure
Class B2 OSSN No complete fix yet, security note for all versions, e.g., poor architecture / design
Class C1 Potential OSSN Not considered a practical vulnerability (but some people might assign a CVE for it)
Class C2 Potential OSSN A vulnerability, but not in OpenStack supported code, e.g., in a dependency
Class D Potential OSSN Not a vulnerability, just a bug with (some) security implications, e.g., strengthening opportunities
Class E Not a vulnerability at all
Class Y Vulnerability only found in development release
Class Z When due process fails

Extent of disclosure

The science of vulnerability management is somewhere around being able to assess impact and severity of a report, being able to design security patches, being an obsessive process-following perfectionist and respecting the rule of lesser disclosure.

Lesser disclosure is about disclosing the vulnerability details to an increasing number of people over time, but only to the people that are necessary to reach the next step. The diagram above shows "disclosure extent" across the various steps of the process.

Vulnerability reporters retain final control over the disclosure of their findings. If for some reason they are uncomfortable with our process, their choice of disclosure terms prevails.

Downstream stakeholders

OpenStack as an upstream project is used in a number of distributions, products, private and public service offerings that are negatively affected by vulnerabilities. In the spirit of responsible disclosure, this ecosystem, collectively known as the downstream stakeholders, needs to be warned in advance to be able to prepare patches and roll them out in a coordinated fashion on disclosure day. The embargo period is kept voluntarily small (3-5 business days), as a middle ground between keeping the vulnerability under cover for too long and not giving a chance to downstream stakeholders to react.

If you're currently not a referenced stakeholder and think you should definitely be included on that email distribution list, please submit an email with a rationale to member(s) of the VMT.


Impact description ($DESCRIPTION)

Title: $TITLE
Reporter: $CREDIT
Products: $PROJECT

$CREDIT reported a vulnerability in... By doing... a... may... resulting in...
Only setups.... are affected.

The AFFECTED_VERSIONS should read like this, while both grizzly and havana still will have point releases:

Versions: from 2011.2 to 2013.1.2, and 2013.2 versions up to 2013.2.1

Once the last Grizzly point release is released, that line becomes:

Versions: from 2011.2 to 2013.2.1

CVE request email (private issues)

  • To: CNA
  • Subject: CVE request for vulnerability in OpenStack $PROJECT
A vulnerability was discovered in OpenStack (see below). In order to
ensure full traceability, we need a CVE number assigned that we can
attach to private and public notifications. Please treat the
following information as confidential until further public


Thanks in advance,

OpenStack Vulnerability Management Team

Email must be GPG-signed and GPG-encrypted.

CVE request email (public issues)

  • To: oss-security@lists.openwall.com
  • Subject: CVE request for vulnerability in OpenStack $PROJECT
A vulnerability was discovered in OpenStack (see below). In order to
ensure full traceability, we need a CVE number assigned that we can
attach to further notifications. This issue is already public, although an
advisory was not sent yet.



Thanks in advance,

OpenStack Vulnerability Management Team

Email must be GPG-signed but not encrypted.

Downstream stakeholders notification email (private issues)

  • To: Downstream stakeholders
  • Subject: [pre-OSSA] Vulnerability in OpenStack $PROJECT ($CVE)
This is an advance warning of a vulnerability discovered in OpenStack,
to give you, as downstream stakeholders, a chance to coordinate the
release of fixes and reduce the vulnerability window. Please treat the
following information as confidential until the proposed public
disclosure date.


Proposed patch:
See attached patches. Unless a flaw is discovered in them, these patches
will be merged to $BRANCHES on the public disclosure date.


Proposed public disclosure date/time:
Please do not make the issue public (or release public patches) before
this coordinated embargo date.


OpenStack Vulnerability Management Team

Proposed patches are attached, email must be GPG-signed. Use something unique and descriptive for the patch attachment file names, for example cve-2013-4183-master-havana.patch or cve-2013-4183-stable-grizzly.patch.

OpenStack Security Advisories

We send two separate emails, to avoid off-topic replies to oss-security list:

  • To: openstack-announce@lists.openstack.org, openstack@lists.openstack.org
  • To: oss-security@lists.openwall.com

Subject and content for both emails is identical:

  • Subject: [OSSA $NUM] $TITLE ($CVE)

OpenStack Security Advisory: $NUM
Date: December 13, 2011

Havana (development branch) fix:

Grizzly fix:

This fix will be included in the $MILESTONE development milestone and in
a future $NEXTSTABLE release.


OpenStack Vulnerability Management Team

  • Email must be GPG-signed.
  • $CVE must always be of the form CVE-YYYY-XXXX
  • $NUM is of the form YYYY-XX