CVE-2021-4329 is a critical-severity (CVSS 9.8) CWE-77 vulnerability in json-logic-js. O3 Security confirms whether CVE-2021-4329 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
json-logic-js Command Injection vulnerability
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
json-logic-jsnpmDescription
A vulnerability, which was classified as critical, has been found in json-logic-js 2.0.0. Affected by this issue is some unknown functionality of the file logic.js. The manipulation leads to command injection. Upgrading to version 2.0.1 is able to address this issue. The patch is identified as c1dd82f5b15d8a553bb7a0cfa841ab8a11a9c227. It is recommended to upgrade the affected component. VDB-222266 is the identifier assigned to this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | json-logic-js | all versions | 2.0.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for json-logic-js. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update json-logic-js to 2.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-4329 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 pinpoints whether CVE-2021-4329 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2021-4329. 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-2021-4329 in your dependencies?
O3 detects CVE-2021-4329 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.