CVE-2018-3770 — markdown-pdf
MEDIUMCVE-2018-3770 is a medium-severity (CVSS 5.5) Path Traversal vulnerability in markdown-pdf. 1 public exploit reference exists, so weaponization risk is real. A fix is available for markdown-pdf — see the affected versions and patch details below.
Remote Code Execution in markdown-pdf
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2018-3770 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
markdown-pdfnpmDescription
Versions of markdown-pdf prior to 9.0.0 are vulnerable to Remote Code Execution. The package fails to sanitize HTML code in markdown files. If markdown files with malicious HTML are converted to PDF, the resulting PDF file will execute any JavaScript code in the original markdown file. This may allow attackers to execute Remote Code.
Recommendation
Upgrade to version 9.0.0 or later.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | markdown-pdf | all versions | 9.0.0npm install markdown-pdf@9.0.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for markdown-pdf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update markdown-pdf to 9.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-3770 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2018-3770 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2018-3770. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2018-3770 in your dependencies?
O3 Security finds CVE-2018-3770 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.