Vulnerability Management Process

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.

Process

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.

VMT Process

Reception

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”). Reports received in private should have their bug description prefaced by an embargo reminder which can be removed once the bug is switched to a public state.

The first steps are to confirm the validity of the report, create a Launchpad bug if necessary, add an ossa bugtask and subscribe the project’s core security review team or Vulnerability Management Liaison for confirmation of impact and determination of affected branches. Reports starting with an “Incomplete” ossa bugtask should have a corresponding incomplete reception message added in a comment. Once we confirm that we will 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, open bug, push patches to Gerrit for review on master and supported stable branches, fast-track approvals (referencing the bug).

Embargo reminder can be removed at that point.

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 to be fixed in master and all supported releases
Class B1 OSSN A vulnerability that can only be fixed in master, security note for stable branches, e.g., default config value is insecure
Class B2 OSSN A vulnerability without a complete fix yet, security note for all versions, e.g., poor architecture / design
Class B3 OSSN A vulnerability in experimental or debugging features not intended for production use
Class C1 Potential OSSN Not considered a practical vulnerability (but some people might assign a CVE for it), e.g. one depending on UUID guessing
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   Neither a vulnerability nor hardening opportunity
Class Y   Vulnerability only found in development release
Class Z   When due process fails

OSSA Task status

Here is a summary of the different OSSA task status meanings:

Status Meaning
Incomplete It is still unclear whenever the bug warrants an advisory
Confirmed The vulnerability is confirmed, impact description is in progress
Triaged Impact description has been submitted for review
In Progress CVE has been requested
Fix committed Pre-OSSA has been communicated
Fix released All patches have been merged
Opinion Issue is likely a Class B/C/D, waiting for OSSN
Won’t Fix Doesn’t fit with the project plans, sorry
Invalid Class E and Z, not a bug or vulnerability. No further action to be taken

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.

Embargo Exceptions

To keep the embargo period short and effective, the VMT may choose to open bug reports. Issues that take too much time to be fixed (e.g., more than 2 weeks) or issues that require a complex patch are usually better solved in the open.

Whenever such a case occurs, the ossg-coresec group is subscribed to the bug report in order to discuss whether or not it’s imperative to keep that particular bug private.

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.

Templates

Reception Incomplete Message (Unconfirmed Issues)

Since this report concerns a possible security risk, an incomplete security advisory task has been added while the core security reviewers for the affected project or projects confirm the bug and discuss the scope of any vulnerability along with potential solutions.

Reception Embargo Reminder (Private Issues)

This issue is being treated as a potential security risk under embargo. Please do not make any public mention of embargoed (private) security vulnerabilities before their coordinated publication by the OpenStack Vulnerability Management Team in the form of an official OpenStack Security Advisory. This includes discussion of the bug or associated fixes in public forums such as mailing lists, code review systems and bug trackers. Please also avoid private disclosure to other individuals not already approved for access to this information, and provide this same reminder to those who are made aware of the issue prior to publication. All discussion should remain confined to this private bug report, and any proposed fixes should be added to the bug as attachments.

Impact Description ($DESCRIPTION)

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

Description:
$CREDIT reported a vulnerability in [project feature name].
By doing [action] a [actor] may [impact] resulting in [consequence].
Only [project deployment mode] are affected.

The AFFECTED_VERSIONS needs to stay valid after the fix is released. For example, when kilo, liberty and mitaka are still security supported, the AFFECTED_VERSIONS of keystone should read like this:

Affects: >=2015.1.0 <=2015.1.4, >=8.0.0 <=8.1.0 and ==9.0.0

Once kilo reaches end of life, that line becomes:

Affects: >=8.0.0 <=8.1.0 and ==9.0.0

If the oldest version affected is not easily identified, leave it open-ended:

Affects: <=8.1.0 and ==9.0.0

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
disclosure.

$DESCRIPTION

Thanks in advance,

--
$VMT_COORDINATOR_NAME
OpenStack Vulnerability Management Team

Email must be GPG-signed and GPG-encrypted.

CVE Request Email (Public Issues)

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.

$DESCRIPTION

References:
https://launchpad.net/bugs/$BUG

Thanks in advance,

--
$VMT_COORDINATOR_NAME
OpenStack Vulnerability Management Team

Email must be GPG-signed but not encrypted.

Downstream Stakeholders Notification Email (Private Issues)

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.

$DESCRIPTION

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

CVE: $CVE

Proposed public disclosure date/time:
$DISCLOSURE, 1500UTC
Please do not make the issue public (or release public patches) before
this coordinated embargo date.

Regards,

--
$VMT_COORDINATOR_NAME
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

The document is first submitted as a yaml description to the ossa project using this template:

date: YYYY-MM-DD

id: OSSA-$NUM

title: '$TITLE'

description: '$DESCRIPTION_CONTENT'

affected-products:

  - product: $PROJECT
    version: $AFFECTED_VERSIONS

vulnerabilities:

  - cve-id: $CVE

reporters:

  - name: '$CREDIT'
    affiliation: $CREDIT_AFFILIATION
    reported:
      - $CVE

issues:

  links:
    - https://launchpad.net/bugs/$BUG

reviews:

  kilo:
    - https://review.openstack.org/$MASTER_REVIEW

  juno:
    - https://review.openstack.org/$STABLE_REVIEW

  type: gerrit

notes:
  - 'Optional note such as cross project version requirements'

Once approved, use the ‘Show Source’ button from the gate-ossa-docs output to get the generated RST document. We send two separate emails, to avoid off-topic replies to oss-security list:

Subject and content for both emails is identical:

  • Subject: [OSSA-$NUM] $TITLE ($CVE)
  • Body: The generated RST document

Notes:

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