Improperly checked IDs on itemstacks received from the client leading to server crash in PocketMine-MP
The advisory, in context
Impact
Due to a workaround for unmapped network items implemented in 4.0.0-BETA5 (8ac16345a3bc099b62c1f5cfbf3b736e621c3f76), arbitrary item IDs are able to be written into an item's NBT. The intended purpose of this is to make said unmapped network items able to be moved around the inventory without issues.
This led to an exploit due to internal limits on the range that item IDs can occupy (-32768 - 32767), while the tag type used to represent the replacement IDs for unknown items is a TAG_Int, allowing a range from -(2^31) - 2^31 - 1. This leads to an uncaught exception which crashes the server.
Patches
5fd685e07d61ef670584ed11a52fd5f4b99a81a7
Workarounds
In theory this can be checked by plugins using a custom TypeConverter, but this is likely to be very cumbersome.
For more information
If you have any questions or comments about this advisory:
- Email us at team@pmmp.io
Affected packages
Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.
From 4.0.0-BETA5 before 4.4.2
Fixed in 4.4.2
43 explicitly affected versions
4.0.0, 4.0.0-BETA10, 4.0.0-BETA11, 4.0.0-BETA12, 4.0.0-BETA13, 4.0.0-BETA14, 4.0.0-BETA15, 4.0.0-BETA5, 4.0.0-BETA6, 4.0.0-BETA7, 4.0.0-BETA8, 4.0.0-BETA9, 4.0.1, 4.0.2, 4.0.3, 4.0.4, 4.0.5, 4.0.6, 4.0.7, 4.0.8, 4.0.9, 4.1.0, 4.1.0-BETA1, 4.1.0-BETA2, 4.2.0, 4.2.1, 4.2.10, 4.2.2, 4.2.3, 4.2.4, 4.2.5, 4.2.6, 4.2.7, 4.2.8, 4.2.9, 4.3.0, 4.3.1, 4.3.2, 4.3.3, 4.3.4, 4.4.0, 4.4.0-BETA1, 4.4.1
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "4.0.0-BETA5"
},
{
"fixed": "4.4.2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.0.0",
"4.0.0-BETA10",
"4.0.0-BETA11",
"4.0.0-BETA12",
"4.0.0-BETA13",
"4.0.0-BETA14",
"4.0.0-BETA15",
"4.0.0-BETA5",
"4.0.0-BETA6",
"4.0.0-BETA7",
"4.0.0-BETA8",
"4.0.0-BETA9",
"4.0.1",
"4.0.2",
"4.0.3",
"4.0.4",
"4.0.5",
"4.0.6",
"4.0.7",
"4.0.8",
"4.0.9",
"4.1.0",
"4.1.0-BETA1",
"4.1.0-BETA2",
"4.2.0",
"4.2.1",
"4.2.10",
"4.2.2",
"4.2.3",
"4.2.4",
"4.2.5",
"4.2.6",
"4.2.7",
"4.2.8",
"4.2.9",
"4.3.0",
"4.3.1",
"4.3.2",
"4.3.3",
"4.3.4",
"4.4.0",
"4.4.0-BETA1",
"4.4.1"
]
}