GMS-2022-3622: PocketMine-MP invalid skin geometry JSON data leading to server crash

Impact

pocketmine\entity\Skin does not correctly handle errors produced by adhocore/json-comment, which throws RuntimeException rather than returning false as PocketMine-MP expects.

This leads to a server crash if the skin geometry data is invalid for some reason (e.g. a syntax error).

Patches

c9626c610b8f6810c8c987559c9197b2a291f0bb

Workarounds

A plugin could handle LoginPacket and PlayerSkinPacket to verify the skin geometry data can be parsed correctly, so that the error condition in the core code is never reached.

For more information

If you have any questions or comments about this advisory:

• Email us at security@pmmp.io