CVE-2015-2156 is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in io.netty:netty-parent. O3 Security confirms whether CVE-2015-2156 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Information Exposure in Netty
Real-World Exposure
io.netty:netty-parent☕org.jboss.netty:netty☕org.jboss.netty:netty☕io.netty:netty☕io.netty:nettyReal-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 before 3.9.8.Final, 3.10.x before 3.10.3.Final, 4.0.x before 4.0.28.Final, and 4.1.x before 4.1.0.Beta5 and Play Framework 2.x before 2.3.9 might allow remote attackers to bypass the httpOnly flag on cookies and obtain sensitive information by leveraging improper validation of cookie name and value characters.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.netty:netty-parent | ≥ 4.0.0&&< 4.0.28.Final | 4.0.28.Final |
| ☕Maven | org.jboss.netty:netty | all versions | 3.9.8.Final |
| ☕Maven | org.jboss.netty:netty | ≥ 3.10.0&&< 3.10.3.Final | 3.10.3.Final |
| ☕Maven | io.netty:netty | ≥ 3.10.0&&< 3.10.3.Final | 3.10.3.Final |
| ☕Maven | io.netty:netty | all versions | 3.9.8.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-parent. 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-parent to 4.0.28.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2015-2156 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-2015-2156 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-2015-2156. 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-2015-2156 in your dependencies?
O3 detects CVE-2015-2156 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.