CVE-2021-21304 is a critical-severity (CVSS 9.8) CWE-915 vulnerability in dynamoose. O3 Security confirms whether CVE-2021-21304 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Prototype Pollution in Dynamoose
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.
dynamoosenpmDescription
Dynamoose is an open-source modeling tool for Amazon's DynamoDB. In Dynamoose from version 2.0.0 and before version 2.7.0 there was a prototype pollution vulnerability in the internal utility method "lib/utils/object/set.ts". This method is used throughout the codebase for various operations throughout Dynamoose. We have not seen any evidence of this vulnerability being exploited. There is no evidence this vulnerability impacts versions 1.x.x since the vulnerable method was added as part of the v2 rewrite. This vulnerability also impacts v2.x.x beta/alpha versions. Version 2.7.0 includes a patch for this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | dynamoose | ≥ 2.0.0&&< 2.7.0 | 2.7.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dynamoose. 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 dynamoose to 2.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21304 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-2021-21304 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-2021-21304. 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-2021-21304 in your dependencies?
O3 detects CVE-2021-21304 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.