CVE-2021-21423
Users of projen's `NodeProject` project type (including any project type derived from it) include a `.github/workflows/rebuild-bot.yml` workflow that may allow any GitHub user to trigger execution of un-trusted code in the context of the "main"…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
`projen` is a project generation tool that synthesizes project configuration files such as `package.json`, `tsconfig.json`, `.gitignore`, GitHub Workflows, `eslint`, `jest`, and more, from a well-typed definition written in JavaScript. Users of projen's `NodeProject` project type (including any project type derived from it) include a `.github/workflows/rebuild-bot.yml` workflow that may allow any GitHub user to trigger execution of un-trusted code in the context of the "main" repository (as opposed to that of a fork). In some situations, such untrusted code may potentially be able to commit to the "main" repository. The rebuild-bot workflow is triggered by comments including `@projen rebuild` on pull-request to trigger a re-build of the projen project, and updating the pull request with the updated files. This workflow is triggered by an `issue_comment` event, and thus always executes with a `GITHUB_TOKEN` belonging to the repository into which the pull-request is made (this is in contrast with workflows triggered by `pull_request` events, which always execute with a `GITHUB_TOKEN` belonging to the repository from which the pull-request is made). Repositories that do not have branch protection configured on their default branch (typically `main` or `master`) could possibly allow an untrusted user to gain access to secrets configured on the repository (such as NPM tokens, etc). Branch protection prohibits this escalation, as the managed `GITHUB_TOKEN` would not be able to modify the contents of a protected branch and affected workflows must be defined on the default branch.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- EPSS
- 1.38% probability · 71th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-527
- Affected
- projen project/projen
- Source
- security-advisories@github.com
References
- https://github.com/projen/projen/commit/36030c6a4b1acd0054673322612e7c70e9446643Patch, Third Party Advisory
- https://github.com/projen/projen/security/advisories/GHSA-gg2g-m5wc-vccqMitigation, Third Party Advisory
- https://www.npmjs.com/package/projenProduct, Third Party Advisory
- https://github.com/projen/projen/commit/36030c6a4b1acd0054673322612e7c70e9446643Patch, Third Party Advisory
- https://github.com/projen/projen/security/advisories/GHSA-gg2g-m5wc-vccqMitigation, Third Party Advisory
- https://www.npmjs.com/package/projenProduct, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.