GHSA-4h8f-2wvx-gg5w
MEDIUMBouncy Castle Java Cryptography API vulnerable to DNS poisoning
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
org.bouncycastle:bcprov-jdk18on☕org.bouncycastle:bcprov-jdk15to18☕org.bouncycastle:bcprov-jdk14☕org.bouncycastle:bcprov-jdk12☕org.bouncycastle:bctls-fips☕org.bouncycastle:bcprov-lts8on☕org.bouncycastle:bcprov-jdk15onReal-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
An issue was discovered in the Bouncy Castle Crypto Package For Java before BC TLS Java 1.0.19 (ships with BC Java 1.78, BC Java (LTS) 2.73.6) and before BC FIPS TLS Java 1.0.19. When endpoint identification is enabled in the BCJSSE and an SSL socket is created without an explicit hostname (as happens with HttpsURLConnection), hostname verification could be performed against a DNS-resolved IP address in some situations, opening up a possibility of DNS poisoning.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.bouncycastle:bcprov-jdk18on | ≥ 1.61&&< 1.78 | 1.78 |
| ☕Maven | org.bouncycastle:bcprov-jdk15to18 | ≥ 1.61&&< 1.78 | 1.78 |
| ☕Maven | org.bouncycastle:bcprov-jdk14 | ≥ 1.61&&< 1.78 | 1.78 |
| ☕Maven | org.bouncycastle:bcprov-jdk12 | ≥ 1.61&&< 1.78 | 1.78 |
| ☕Maven | org.bouncycastle:bctls-fips | all versions | 1.0.19 |
| ☕Maven | org.bouncycastle:bcprov-lts8on | all versions | 2.73.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.bouncycastle:bcprov-jdk18on. 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 org.bouncycastle:bcprov-jdk18on to 1.78 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4h8f-2wvx-gg5w 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-4h8f-2wvx-gg5w 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-4h8f-2wvx-gg5w. 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-4h8f-2wvx-gg5w in your dependencies?
O3 detects GHSA-4h8f-2wvx-gg5w across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.