CVE-2025-25193 is a medium-severity (CVSS 5.5) Uncontrolled Resource Consumption vulnerability in io.netty:netty-common. O3 Security confirms whether CVE-2025-25193 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Denial of Service attack on windows app using Netty
Real-World Exposure
io.netty:netty-commonReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Netty, an asynchronous, event-driven network application framework, has a vulnerability in versions up to and including 4.1.118.Final. An unsafe reading of environment file could potentially cause a denial of service in Netty. When loaded on an Windows application, Netty attempts to load a file that does not exist. If an attacker creates such a large file, the Netty application crash. A similar issue was previously reported as CVE-2024-47535. This issue was fixed, but the fix was incomplete in that null-bytes were not counted against the input limit. Commit d1fbda62d3a47835d3fb35db8bd42ecc205a5386 contains an updated fix.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.netty:netty-common | all versions | 4.1.118.Final |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty:netty-common. 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 io.netty:netty-common to 4.1.118.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-25193 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-2025-25193 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-2025-25193. 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-2025-25193 in your dependencies?
O3 detects CVE-2025-25193 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.