Vulnerability · Published Apr 6, 2021 · Assigned by GitHub_M
CVE-2021-21423Exposure of Version-Control Repository to an Unauthorized Control Sphere in projen
Medium 6.8
In plain English
A medium-severity security flaw in projen from projen. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.4% (higher than 72% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | projen | 0.16.41 | GHSA-gg2g-m5wc-vccq |
| PyPI | projen | 0.16.41 | PYSEC-2021-111 |
| npm | projen | 0.16.41 | GHSA-gg2g-m5wc-vccq |
Affected products (as reported)
Weakness: CWE-527 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
References
- https://github.com/projen/projen/security/advisories/GHSA-gg2g-m5wc-vccq x_refsource_CONFIRM
- https://github.com/projen/projen/commit/36030c6a4b1acd0054673322612e7c70e9446643 x_refsource_MISC
- https://www.npmjs.com/package/projen x_refsource_MISC