Security response team guidelines

These are the guidelines for OpenBMC security responders, including the security response team, project owners, and community members who are responding to problems reported by the security vulnerability reporting process.

Each project within OpenBMC works independently to resolve security vulnerabilities. The security response team helps the maintainers, provides consistency within the OpenBMC project, and helps to get CVEs assigned.

Here are the primary expectations:

• Keep problems private until announce.
• Work with diligence.
• Keep stakeholders informed.

Workflow highlights:

1. Handle new problem reports.

   • Within a day, acknowledge you received the report. Note that reports are archived in the mailing list.
   • Communicate by opening the GitHub draft security advistory as soon as the problem is known.

2. Analyze the problem and engage collaborators as needed (upstream, downstream, and OpenBMC).

   • Determine if the problem is new or known.
   • Determine if the problem is in OpenBMC.
     • If the problem is in a project that OpenBMC uses, re-route the problem to that upstream project.
     • Note that the problem may be in a customized version of OpenBMC but not in OpenBMC itself.
   • Determine which OpenBMC areas should address the problem.
   • Create the draft security advisory and populate its fields.
     • The Ecosystem would normally be "OpenBMC" and the package name is normally the repository.
     • Please describe when the problem was introduced to help users learn if they are affected. Use Git tags and commit IDs if known. It also may be helpful to say what OpenBMC version is affected. For example, if the problem in the original code through OpenBMC release 2.9, the affected version is "<= 2.9". See OpenBMC releases.
   • Use private channels, for example, email, GitHub draft security advistory, or private direct messaging.
   • Inform contacts this is private work as part of the OpenBMC security response team. For example, link to these guidelines.
   • Coordinate with all collaborators and keep them informed.

   Considerations in the CERT Guide to Coordinated Vulnerability Disclosure (SPECIAL REPORT CMU/SEI-2017-SR-022) may guide the process.

   Example collaborations:

   • Submit the problem to another security response team, for example, the UEFI Security Response Team (USRT).
   • Privately engage an OpenBMC maintainer or subject matter expert.

3. For OpenBMC problems.

   1. Determine if this is a high severity problem. Example using CVSS metrics: a remotely exploitable or low complexity attack that has high impact to the BMC's confidentiality, integrity, or availability.
   2. Avoid pre-announcing problems. Be especially careful with high severity problems. When fixing the problem, use the contribution process but limit the details in the issue or use a private channel to discuss.
   3. Negotiate how the code review will proceed.
      • Consider contributing using a Gerrit private change if everyone has access to Gerrit.
      • Consider using Patch set emails to make reviews accessible to all stakeholders.
   4. When agreed:
      • Publish a security advisory to the affected OpenBMC repository.
      • Make the Gerrit review publicly viewable.
      • Publish the CVE in the CVE database.
   5. Improve OpenBMC processes to avoid future problems.

Repository maintainer process steps: 1. Create a private gerrit code review and oversee development of the fix. 2. Create a draft advisory under github.com/openbmc//security/advisories. Please follow guidance in the OpenBMC Security Advisory Template. Add the openbmc security-response group and other stakeholders to the advisory. 3. Review the security bulletin with stakeholders to get it ready to publish. 4. Work with the SRT to identify CVEs. If you are unsure what counts as a vulnerability, please consult with the SRT. For example, independent bugs should have separate CVEs. A security advisory can reference multiple CVEs. When the CVE is known, add it to the security advisory, and reference it in the commit message, stating how the fix relates to the CVE. For example: This fixes CVE-yyyy-nnnnn. Doing so helps downstream security responders. If the commit is a partial fix, please explain that and provide references to the other parts of the fix. 5. If stakeholders negotiate for coordinated disclosure, plan to release the fix and the security advisory on the negotiated day. 6. When the code fix and the advisory are both ready (subject to coordinated disclosure), please merge the fixes (and make any private review be public) publish the security advisory, and email the security-response team.

Template: Initial response to the problem submitter

The OpenBMC security response team has received the problem.

• Thank you for reporting this.
• Share preliminary results of the analysis.
• Share preliminary OpenBMC plans or that we are analyzing the problem.
• Set expectations for follow-up communications.

Template: OpenBMC Security Advisory

OpenBMC Security Advisory
Title: ...

...summary: include CVEs, releases affected, etc....

The CVSS score for these vulnerabilities is "...", with temporal score
"...", with the following notes:
https://www.first.org/cvss/calculator/3.0

The fix is in the https://github.com/openbmc/... repository as git
commit ID ....

For more information, see OpenBMC contact information at
https://github.com/openbmc/openbmc file README.md.

Credit for finding these problems: ...

Template: Security Advisory notice

When the Security Advisory is created, inform the OpenBMC community by sending email like this:

TO: openbmc-security@lists.ozlabs.org, openbmc@lists.ozlabs.org
SUBJECT: [Security Advisory] ${subject}

The OpenBMC Security Response team has released an OpenBMC Security Advisory:
${url}

An OpenBMC Security Advisory explains a security vulnerability, its severity,
and how to protect systems that are built on OpenBMC.  For more information
about OpenBMC Security Response, see:
https://github.com/openbmc/docs/blob/master/security/obmc-security-response-team.md

Reference

Some of these guidelines were collected from:

• https://bestpractices.coreinfrastructure.org/en/projects/34
• https://www.kernel.org/doc/html/v4.16/admin-guide/security-bugs.html
• https://oss-security.openwall.org/wiki/mailing-lists/distros
• ISO/IEC 29147:2018 vulnerability disclosure

Team composition and email maintenance

The security response team (SRT) is controlled by the OpenBMC Technical Steering Committee, including membership on the team. General considerations for SRT membership:

• Although individuals join the SRT, it is really organizations which join as represented by their SRT members. The SRT members are expected to:
  • Participate in their organization's SRT.
  • Designate backup OpenBMC SRT members.
  • Share OpenBMC security vulnerability information within their organization with the same care as stated in this document.
• Membership is intended for organizations which have a vested interest in OpenBMC security response. Here are some examples to consider:
  • Organizations which have products or services built on OpenBMC which are publicly available and disclose security bugs to their users.  This includes systems directly built on OpenBMC, and larger systems such as data centers.
  • Organizations which focus on BMC security research or security response.
• Evaluation of an organization may be based on its members' OpenBMC community roles, technical skills, and expertise responding to security incidents.
• Membership should not be granted without compelling reason. The intention is to avoid premature disclosure of security vulnerabilities by limiting membership to those with vested interest.

The security response team uses the openbmc-security at lists.ozlabs.org private email list as a channel for confidential communication, so its membership reflects the composition of the security response team. The list membership should be reviewed periodically and can be managed from https://lists.ozlabs.org/listinfo/openbmc-security.

The email list subscribers should be reminded periodically to protect access to the emails from the list because of the sensitive information they contain.

The email list membership is not intended to be secret. For example, we can discuss it a public forum. However, no effort is made to make the list's membership public.

The email list identification is for privately reporting OpenBMC security vulnerabilities with description: This email list is for privately reporting OpenBMC security vulnerabilities. List membership is limited to the OpenBMC security response team. For more information, see https://github.com/openbmc/docs/blob/master/security/how-to-report-a-security-vulnerability.md

Sample response for denying list membership:

Thanks for your interest in OpenBMC security.  Subscriptions to the
openbmc-security@lists.ozlabs.org email list are by invitation only
and are typically extended only to security response team members.
For more information, see https://github.com/openbmc/docs/security or
attend a security working group meeting:
https://github.com/openbmc/openbmc/wiki/Security-working-group.

Yours truly,
OpenBMC security response team