CVE-2021-39177
Severity CVSS v4.0:
Pending analysis
Type:
CWE-287
Authentication Issues
Publication date:
30/08/2021
Last modified:
10/09/2021
Description
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 for the issue. There are no known workarounds aside from upgrading.
Impact
Base Score 3.x
9.80
Severity 3.x
CRITICAL
Base Score 2.0
7.50
Severity 2.0
HIGH
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:a:geysermc:geyser:*:*:*:*:*:*:*:* | 1.4.2 (excluding) |
To consult the complete list of CPE names with products and versions, see this page



