Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Search

GHSA-gg2g-m5wc-vccq

MediumCVSS 6.8 / 10
Published Apr 6, 2021·Last modified Mar 13, 2026
Affected Components(0)

No affected components available

Description

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.

Risk Scores
Base Score
6.8

The vulnerability can be exploited over the network without needing physical access. It is difficult for an attacker to exploit this vulnerability and may require special conditions. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data.

Threat Intelligence
6.2

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
1.38%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard