Handling Go Vulnerability Reports

This document explains how we handle vulnerability issue triage in the x/vulndb issue tracker.

Reports

All vulnerabilities in the Go vulnerability database are currently stored as a YAML file in the data/reports or data/excluded directory.

For a detailed explanation of the report format and style guide, see doc/format.md.

Issue States

Any open issue should be in one of the following states:

  • New (no label)
  • Needs investigation
  • Needs report
  • Excluded
  • Out of scope

Maintainers of the Go vulndb move issues from one state to another. The intent behind these explicit states is to describe the (minimum) next steps required to bring the issue to resolution.

New (untriaged)

The issue has been filed by the vulndb worker or an external reporter.

The issue will have the title: x/vulndb: potential Go vuln in <module/package>: <CVE ID and or GHSA ID>.

To transition from this state, do one of the following:

  • Label the issue as NeedsInvestigation, and discuss the issue with the team.
  • Label the issue as excluded: REASON, and use the vulnreport create-excluded command to create a CL.
  • Label the issue as NeedsReport, and use the vulnreport tool to assist in creating a CL.
  • Label the issue as excluded: OUT_OF_SCOPE and close the issue.
  • Label the issue as duplicate and close the issue.

Needs Investigation

Label: NeedsInvestigation

This state is used when it is not clear how to proceed. (Otherwise, an issue can move straight to one of the other states.)

Make a plan to discuss the issue with the team to determine a course of action.

Needs Report

Label: NeedsReport

The issue has been confirmed to be an in-scope Go vulnerability, and a report needs to be added to data/reports.

Excluded

Label: excluded: REASON where REASON is one of the possible excluded reasons.

The issue represents a reported vulnerability, but is not in scope for the main data/reports folder. An “excluded” report needs to be added to data/excluded.

Out-of-scope

Label: excluded: OUT_OF_SCOPE or duplicate.

The issue is out of scope for both the data/reports and data/excluded folders. For example, it is an issue mistakenly posted to the tracker (excluded: OUT_OF_SCOPE) or a duplicate (duplicate) of another issue.

The issue can be closed without further action.

Adding new reports

One-time setup

  1. Clone the x/vulndb repository: git clone https://go.googlesource.com/vulndb.

  2. Get a GitHub access token with scope repo: public_repo (follow instructions for “personal access token (classic)”).

    Store the token in a file, e.g., ~/.github-token, and run: export VULN_GITHUB_ACCESS_TOKEN=`cat ~/.github-token` (you can also store this command in a ~/.bashrc file or similar).

  3. Run go install ./cmd/vulnreport to install the latest version of vulnreport tool

Add a new report (label NeedsReport)

  1. Sync your git repo, re-install the vulnreport tool, and create a fresh branch.
  2. From the repo root, run vulnreport create <GitHub issue number>. The vulnreport tool will create a YAML report template for the CVE or GHSA at the specified GitHub issue number. This command works for both regular reports and excluded reports. It also accepts multiple Github issue numbers (space separated), and Github issue ranges (e.g., 1000-1010).
  3. Edit the report file template, following the guidance in doc/format.md. A few tips:
    • If a person or organization is given credit in the CVE or GHSA, add the name to the “credit” field. Otherwise, delete the field.
    • In the “vulnerable_at” field, put the highest version just before the vuln is fixed. The pkgsite versions page can help with the list of versions. The GitHub UI also makes it easy to list tags (click “Code”, then the dropdown that shows the current branch, then “Tags”). Walk the versions backwards from the fixed one to find the highest that doesn't contain the fix. (It might not be the immediately preceding version.)
    • Add vulnerable functions to the “symbols” list by reading the CVE, the fixing CLs, and the code at the vulnerable version you chose above.
  4. From the repo root, run vulnreport fix <GitHub issue number>. This will lint the report, add exported symbols, and convert the YAML to OSV.
  5. Once any errors are fixed, run vulnreport commit <GitHub issue number>. This will create a git commit containing the new files with a standard commit message. Commits are to the local git repository. The vulnreport commit command also accepts multiple space-separated issue numbers, and will create a separate commit for each report.
  6. Send the commit for review and approval. See the Go contribution guide for sending a change on Gerrit.
  7. If you make changes to the report during review, re-run vulnreport fix <GitHub issue number> before re-mailing to update the OSV and make sure the report is still valid.

Batch add excluded reports (label excluded: REASON)

  1. Sync your git repo, re-install the vulnreport tool, and create a fresh branch.
  2. Run vulnreport create-excluded. This will batch create YAML reports for all issues with the excluded: REASON label. If there is an error creating any given report, the skipped issue number will be printed to stdout and that issue will have to be created manually with vulnreport create <Github issue number>. (see steps 2-4 above for more information). Additionally, create-excluded will automatically create a single commit for all successful reports.
  3. Send the commit for review and approval. See the Go contribution guide for sending a change on Gerrit.

Handling duplicates

Sometimes an issue describes a vulnerability that we already have a report for. The worker doesn't always detect this automatically, so it is a good idea to grep the /data directory of this repo for the module path and read the report to see if the vulns are the same.

If the issue is indeed a duplicate:

  1. Apply the label duplicate to the issue.
  2. Find the duplicate issue (say it is #NNN) in the issue tracker, and on the current issue, write the comment “Duplicate of #NNN”. (No period after the number.)
  3. If a report has already been created for #NNN:
    1. Find the report yaml file (say GO-YYYY-NNNN.yaml) in data/reports, and add the duplicate IDs to the cves or ghsas section, as appropriate. Running vulnreport fix can sometimes find the IDs automatically. (If the duplicate IDs are already present, close the GH issue.)
    2. On a new branch, run vulnreport -up commit NNN to update generated files and create a commit. Edit the generated commit message so that it includes the words “add aliases”. You can also add “Fixes #DDDD” (the number of the duplicate issue) to the commit message, or close it manually.
    3. Mail the commit.
  4. If no report has been created for #NNN yet, make sure the duplicate ID is present somewhere in issue #NNN for reference, and close the duplicate issue.

Standard Library Reports

When adding a vulnerability report about the standard library, ensure that the references section follows this format:

references:
- report: https://go.dev/issue/<#>
- fix: https://go.dev/cl/<#>
- web: https://groups.google.com/g/golang-announce/c/<XXX>/<YYY>

You can find these links in the golang-announce@ email for the security release fixing this vulnerability.

Report: The Github issue will be listed in the golang-announce@ email.

Fix: The PR will be a go.dev/cl/<#> link, found as a gopherbot comment on the issue for the vulnerability.

Web: The golang-announce email link.

Updating a report

Occasionally, we will receive new information about a Go vulnerability and want to update the existing report.

In that case, reopen the issue for the report to discuss the change, rather than create a new issue.

The command vulnreport -up commit NNN can be used to create a more sensible commit message when committing an updated report.

Frequent issues during triage

This section describes frequent issues that come up when triaging vulndb reports.

vulnreport cgo failures

When vulnreport fix fails with an error message like

/path/to/package@v1.2.3/foo.go:1:2: could not import C (no metadata for C)

a frequent cause is the local machine missing C library headers causing typechecking of cgo packages to fail. The easiest workaround is to use a machine with the development headers installed or to install them.

Commonly missing packages include:

  • libgpgme-dev
  • libdevmapper-dev