CVE-2019-11808
LOWUse of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in Ratpack
Blast Radius
io.ratpack:ratpack-session☕io.ratpack:ratpack-java☕io.ratpack:ratpack-groovyReal-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
Ratpack versions before 1.6.1 generate a session ID using a cryptographically weak PRNG in the JDK's ThreadLocalRandom. This means that if an attacker can determine a small window for the server start time and obtain a session ID value, they can theoretically determine the sequence of session IDs.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.ratpack:ratpack-session | all versions | 1.6.1 |
| ☕Maven | io.ratpack:ratpack-java | all versions | 1.6.1 |
| ☕Maven | io.ratpack:ratpack-groovy | all versions | 1.6.1 |
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-session. 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-session to 1.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-11808 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-2019-11808 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-2019-11808. 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-2019-11808 in your dependencies?
O3 detects CVE-2019-11808 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.