ghsa-gg2g-m5wc-vccq
Vulnerability from github
7.6 (High) - CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Impact
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.
Patches
The issue was mitigated in version 0.16.41
of the projen
tool, which removes the issue_comment
trigger from this workflow. Version 0.17.0
of projen completely removes the rebuild-bot.yml
workflow.
Workarounds
The recommended way to address the vulnerability is to upgrade projen
. Users who cannot upgrade projen
may also remove the .github/workflows/rebuild-bot.yml
file and add it to their .gitignore
file (via projenrc.js
) to mitigate the issue.
References
The rebuild-bot.yml
workflow managed by projen
is only one occurrence of a GitHub Workflows mis-configuration, but it may also be present in other workflows not managed by projen
(either hand-written, or managed by other tools). For more information on this class of issues, the Keeping your GitHub Actions and workflows secure: Preventing pwn requests article provides a great overview of the problem.
{ "affected": [ { "package": { "ecosystem": "npm", "name": "projen" }, "ranges": [ { "events": [ { "introduced": "0.6.0" }, { "fixed": "0.16.41" } ], "type": "ECOSYSTEM" } ] }, { "package": { "ecosystem": "PyPI", "name": "projen" }, "ranges": [ { "events": [ { "introduced": "0" }, { "fixed": "0.16.41" } ], "type": "ECOSYSTEM" } ] } ], "aliases": [ "CVE-2021-21423" ], "database_specific": { "cwe_ids": [ "CWE-527" ], "github_reviewed": true, "github_reviewed_at": "2021-04-06T18:36:19Z", "nvd_published_at": "2021-04-06T19:15:00Z", "severity": "HIGH" }, "details": "### Impact\n\n`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\u0027s `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.\n\nThe 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).\n\nRepositories 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. \n\n### Patches\n\nThe issue was mitigated in version `0.16.41` of the `projen` tool, which removes the `issue_comment` trigger from this workflow. Version `0.17.0` of projen completely removes the `rebuild-bot.yml` workflow.\n\n### Workarounds\n\nThe recommended way to address the vulnerability is to upgrade `projen`. Users who cannot upgrade `projen` may also remove the `.github/workflows/rebuild-bot.yml` file and add it to their `.gitignore` file (via `projenrc.js`) to mitigate the issue.\n\n### References\n\nThe `rebuild-bot.yml` workflow managed by `projen` is only one occurrence of a GitHub Workflows mis-configuration, but it may also be present in other workflows not managed by `projen` (either hand-written, or managed by other tools). For more information on this class of issues, the [Keeping your GitHub Actions and workflows secure: Preventing pwn requests][1] article provides a great overview of the problem.\n \n\n[1]: https://securitylab.github.com/research/github-actions-preventing-pwn-requests", "id": "GHSA-gg2g-m5wc-vccq", "modified": "2024-10-21T20:05:47Z", "published": "2021-04-06T18:36:40Z", "references": [ { "type": "WEB", "url": "https://github.com/projen/projen/security/advisories/GHSA-gg2g-m5wc-vccq" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-21423" }, { "type": "WEB", "url": "https://github.com/projen/projen/commit/36030c6a4b1acd0054673322612e7c70e9446643" }, { "type": "PACKAGE", "url": "https://github.com/projen/projen" }, { "type": "WEB", "url": "https://github.com/pypa/advisory-database/tree/main/vulns/projen/PYSEC-2021-111.yaml" }, { "type": "WEB", "url": "https://www.npmjs.com/package/projen" } ], "schema_version": "1.4.0", "severity": [ { "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N", "type": "CVSS_V3" }, { "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N", "type": "CVSS_V4" } ], "summary": "Rebuild-bot workflow may allow unauthorised repository modifications" }
Sightings
Author | Source | Type | Date |
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Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.