GHSA-w6rq-6h34-vh7q
HIGHGHSA-w6rq-6h34-vh7q is a high-severity (CVSS 7) CWE-807 vulnerability in io.ratpack:ratpack-core. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-w6rq-6h34-vh7q is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cached redirect poisoning via X-Forwarded-Host header
Real-World Exposure
io.ratpack:ratpack-coreReal-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
A user supplied X-Forwarded-Host header can be used to perform cache poisoning of a cache fronting a Ratpack server if the cache key does not include the X-Forwarded-Host header as a cache key.
Users are only vulnerable if they do not configure a custom PublicAddress instance. A custom PublicAddress can be specified by using ServerConfigBuilder::publicAddress. For versions prior to 1.9.0, by default, Ratpack utilizes an inferring version of PublicAddress which is vulnerable.
Impact
This can be used to perform redirect cache poisoning where an attacker can force a cached redirect to redirect to their site instead of the intended redirect location.
Patches
As of Ratpack 1.9.0, two changes have been made that mitigate this vulnerability:
- The default PublicAddress implementation no longer infers the address from the request context, instead relying on the configured bind host/port
- Relative redirects issued by the application are no longer absolutized; they are passed through as-is
Workarounds
In production, ensure that ServerConfigBuilder::publicAddress correctly configures the server.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.ratpack:ratpack-core | all versions | 1.9.0 |
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 io.ratpack:ratpack-core. 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.ratpack:ratpack-core to 1.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w6rq-6h34-vh7q 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 GHSA-w6rq-6h34-vh7q 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 GHSA-w6rq-6h34-vh7q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-w6rq-6h34-vh7q in your dependencies?
O3 detects GHSA-w6rq-6h34-vh7q across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.