CVE-2022-51017
highpriority · track · 30EPSS 0.006 · 50 %ileUSEPSS · scored 2026-10-26
PocketMine-MP versions before 3.26.5 and 4.0.5 fail to validate the length of skin data fields submitted by players, allowing uncapped values to exceed the 32767 byte TAG_String limit. Attackers can submit oversized skin data fields like skinID or geometryName to trigger exceptions during NBT data serialization, causing server crashes.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (2)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-c6fg-99pr-25m9Uncapped length of skin data fields submitted by players2022-01-06ghsa · osvUS
### Impact Some skin data fields (e.g. skinID, geometryName) are not capped in length. These fields are typically saved in the NBT data of a player when the player quits the server, or during an autosave. This is problematic due to the 32767 byte limit on `TAG_String`s. If any of these fields exceeds 32767 bytes, an exception will be thrown during data saving, which will cause the server to crash. Other fields (such as skinGeometryData) are also uncapped, but those have a much larger 2 GB length limit, so this is not a concern for those, particularly considering the decompressed packet size limit of 2 MB. ### Patches PM3: 958a9dbf0fe3131ab60319c5a939f5dfbfe5dfbb PM4: 6492cac5c10f9fa8443ceddd2191a7b65b73f601 ### Workarounds A plugin may check player skins during `PlayerLoginEvent` and `PlayerSkinChangeEvent` and ensure that the offending fields are not larger than 32767 bytes. ### For more information If you have any questions or comments about this advisory: * Email us at [team@pmmp.io](mailto:team@pmmp.io)
sources
Which sources assert this record, and when.
references (4) nvd
External citations — patches, advisories, analysis.
- https://github.com/pmmp/PocketMine-MP/commit/6492cac5c10f9fa8443ceddd2191a7b65b73f601
- https://github.com/pmmp/PocketMine-MP/commit/958a9dbf0fe3131ab60319c5a939f5dfbfe5dfbb
- https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-c6fg-99pr-25m9
- https://www.vulncheck.com/advisories/pocketmine-mp-before-3.26.5-and-4.0.5-denial-of-service-via-skin-data
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