Auth bypass in Geysermc Geyser

CVE-2021-39177

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 impersonat…

Vulnerability class: Broken Authentication

EPSS: 0.004 (57.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-39177?
CVE-2021-39177 is a high-severity vulnerability in Geysermc Geyser, classified under Improper Authentication. CVSS score: 7.4/10. Published 2021-08-30.
How severe is CVE-2021-39177?
High severity. CVSS v3 base score is 7.4 out of 10.