Code Injection in md-to-pdf (CVE-2021-23639)
Summary
Code injection in md-to-pdf (CVE-2021-23639). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 5.0.0 or later.
Original description
The description as published by the source.
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.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2021-23639 has been found in md-to-pdf.
Successful exploitation can lead to full system takeover.
What to do: upgrade md-to-pdf to 5.0.0 or later.
If unsure, ask your IT team or search "md-to-pdf CVE-2021-23639" on the vendor's site.
CVE-2021-23639 (md-to-pdf) — CWE-94
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 5.0.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Arbitrary code execution (CWE-94) exists in md-to-pdf.
Check the vendor advisory for the affected versions of md-to-pdf.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 5.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'md-to-pdf' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'md-to-pdf' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
md-to-pdfを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade md-to-pdf to 5.0.0ステージング環境で 5.0.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web snyk.io