Auth bypass in Tgstation Tgstation-Server

CVE-2025-21611

tgstation-server is a production scale tool for BYOND server management. Prior to 6.12.3, roles used to authorize API methods were incorrectly OR'd instead of AND'ed with the role used to determine if a user was enabled. This allows enabled users access to most, but not all, authorized actions regardless of their permissions. Notably, the WriteUsers right is unaffected so users may not use this bug to permanently elevate their account permissions. The fix is release in tgstation-server-v6.12.3.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (40.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-21611: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-21611?
CVE-2025-21611 is a high-severity vulnerability in Tgstation Tgstation-Server, classified under Improper Authorization. CVSS score: 8.8/10. Published 2025-01-06.
How severe is CVE-2025-21611?
High severity. CVSS v3 base score is 8.8 out of 10.