GHSA-5jfw-35xp-5m42
HIGHGHSA-5jfw-35xp-5m42 is a high-severity (CVSS 7.5) vulnerability in pocketmine/bedrock-protocol. O3 Security confirms whether GHSA-5jfw-35xp-5m42 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Buffer length underflow in LoginPacket causing unchecked exceptions to be thrown
Blast Radius
pocketmine/bedrock-protocolReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
LoginPacket uses BinaryStream->getLInt() to read the lengths of JSON payloads it wants to decode. Unfortunately, BinaryStream->getLInt() returns a signed integer, meaning that a malicious client can craft a packet with a large uint32 value for payload buffer size (which would be interpreted as a negative signed int32), causing BinaryStream->get() to throw an exception.
In the context of PocketMine-MP, this leads to a server crash when the vulnerability is exploited.
Patches
e3fce7632b94e83fd6a518a87dcaf6a11681c4ac
Workarounds
This can be worked around by registering a custom LoginPacket implementation into PacketPool which overrides this code to patch it.
For more information
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | pocketmine/bedrock-protocol | all versions | 8.0.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pocketmine/bedrock-protocol. 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 pocketmine/bedrock-protocol to 8.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5jfw-35xp-5m42 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-5jfw-35xp-5m42 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-5jfw-35xp-5m42. 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-5jfw-35xp-5m42 in your dependencies?
O3 detects GHSA-5jfw-35xp-5m42 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.