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MEDIUM5.3

GHSA-g274-c6jj-h78p

PocketMine-MP allows malicious client data to waste server resources due to lack of limits for explode()

Quick fix

GHSA-g274-c6jj-h78p — pocketmine/pocketmine-mp: upgrade to the fixed version with the command below.

composer require pocketmine/pocketmine-mp:^5.25.2

Details

### Impact Due to lack of limits by default in the [`explode()`](https://www.php.net/manual/en/function.explode.php) function, malicious clients were able to abuse some packets to waste server CPU and memory.

This is similar to a previous security issue published in https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-gj94-v4p9-w672, but with a wider impact, including but not limited to:

- Sign editing - LoginPacket JWT parsing - Command parsing

However, the estimated impact of these issues is low, due to other limits such as the packet decompression limit.

### Patches The issue was fixed in 5.25.2 via d0d84d4c5195fb0a68ea7725424fda63b85cd831.

A custom PHPStan rule has also been introduced to the project, which will henceforth require that all calls to `explode()` within the codebase must specify the `limit` parameter.

### Workarounds No simple way to fix this. Given that sign editing is the easiest way this could be exploited, workarounds could include plugins pre-processing `BlockActorDataPacket` to check that the incoming text doesn't have more than 4 parts when split by `\n`.

Are you affected?

Enter the version of the package you're using.

Affected packages

Packagist/pocketmine/pocketmine-mp
Introduced in: 0Fixed in: 5.25.2
Fixcomposer require pocketmine/pocketmine-mp:^5.25.2

References