CVE-2024-27931
MEDIUMCVE-2024-27931 is a medium-severity (CVSS 5.8) Improper Input Validation vulnerability in deno. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2024-27931 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Insufficient permission checking in `Deno.makeTemp*` APIs
Real-World Exposure
denoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. Insufficient validation of parameters in Deno.makeTemp* APIs would allow for creation of files outside of the allowed directories. This may allow the user to overwrite important files on the system that may affect other systems. A user may provide a prefix or suffix to a Deno.makeTemp* API containing path traversal characters. This is fixed in Deno 1.41.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | deno | all versions | 1.41.1 |
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 deno. 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 deno to 1.41.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-27931 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-2024-27931 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-2024-27931. 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-2024-27931 in your dependencies?
O3 detects CVE-2024-27931 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.