PocketMine-MP vulnerable to server crash with certain invalid JSON payloads in…
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from GitHub.
Summary
### Impact An attacker could crash PocketMine-MP by sending malformed JSON in `LoginPacket`. This happened due to a bug in [`netresearch/jsonmapper`](https://github.com/cweiske/JsonMapper). The library wasn't doing proper checks when mapping JSON arrays and objects onto scalar model properties such as strings. ### Patches The problem was fixed in a fork of JsonMapper in dktapps/JsonMapper@a31902a31f5b6fdb832f57c0e3a3f16a3b41c012. PocketMine-MP releases 4.20.5 and 4.21.1 have been released with the fix. ### Workarounds - Users of PocketMine-MP source installations may manually install the patched version of JsonMapper by backporting commit pmmp/PocketMine-MP@09668a37d66c6023685a948b7550c918620e98f2. - A plugin may also be able to workaround this issue by using `DataPacketReceiveEvent` to attempt detection of suspicious payloads. An `ErrorException` will be thrown in the crash case, which can be caught by plugins. ### References cweiske/jsonmapper#210
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | pocketmine/pocketmine-mp (Packagist) | before 4.20.5 | 4.20.5 | Patch available | GHSA-pqp3-8rrw-g8vm |
| — | pocketmine/pocketmine-mp (Packagist) | 4.21.0 to before 4.21.1 | 4.21.1 | Patch available | GHSA-pqp3-8rrw-g8vm |
- pocketmine/pocketmine-mp (Packagist) Vendor— Affected before 4.20.5 Fixed in 4.20.5 Patch available GHSA-pqp3-8rrw-g8vm
- pocketmine/pocketmine-mp (Packagist) Vendor— Affected 4.21.0 to before 4.21.1 Fixed in 4.21.1 Patch available GHSA-pqp3-8rrw-g8vm
Remediation
- Fix · GHSA-pqp3-8rrw-g8vm pocketmine/pocketmine-mp (Packagist) Fixed in 4.20.5 Advisory →
- Fix · GHSA-pqp3-8rrw-g8vm pocketmine/pocketmine-mp (Packagist) Fixed in 4.21.1 Advisory →
Timeline
- 2026-10-03 Threatist record created from GHSA-pqp3-8rrw-g8vm
References
Other 5
- https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-pqp3-8rrw-g8vm
- https://github.com/cweiske/jsonmapper/pull/210
- https://github.com/pmmp/PocketMine-MP/commit/09668a37d66c6023685a948b7550c918620e98f2
- https://github.com/pmmp/netresearch-jsonmapper/commit/a31902a31f5b6fdb832f57c0e3a3f16a3b41c012
- https://github.com/pmmp/PocketMine-MP
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences