CVE-2021-39177 User impersonation due to incorrect handling of the login JWT

Geyser is a bridge between Minecraft: Bedrock Edition and Minecraft: Java Edition. Versions of Geyser prior to 1.4.2-SNAPSHOT allow anyone that can connect to the server to forge a LoginPacket with manipulated JWT token allowing impersonation as any user. Version 1.4.2-SNAPSHOT contains a patch f...

CVE-2021-39177

Summary: CVE-2021-39177 affects Geyser versions prior to 1.4.2-SNAPSHOT, where an attacker who can connect to a server can forge a LoginPacket with a manipulated JWT token to impersonate any user. The issue is mitigated by upgrading to 1.4.2-SNAPSHOT or later, which includes a patch. Other workar...