CVE-2022-21165 — font-converter
CRITICALCVE-2022-21165 is a critical-severity (CVSS 9.8) remote code execution vulnerability in font-converter. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
Font-Converter Vulnerable to Arbitrary Command Injection
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-2022-21165 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.
font-converternpmDescription
Overview
font-converter is a FontForge wrapper that allows conversion between different font formats (TTF, WOFF, OTF)
All versions of this package are vulnerable to Arbitrary Command Injection due to missing sanitization of input that potentially flows into the child_process.exec() function.
PoC
var PUT = require('font-converter');
var x = "$(touch success);# ";
try {
new PUT(x, x, x, x);
} catch (e) {
console.log(e);
}
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | font-converter | all versions | No fix |
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 font-converter, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of font-converter has shipped for CVE-2022-21165 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2022-21165 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-21165. 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-2022-21165 in your dependencies?
O3 Security finds CVE-2022-21165 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.