CVE-2025-21611: tgstation-server Access Control Flaw

Description

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.

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CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-285 CWE-285

Affected Products

Vendor	Product	Versions
tgstation13	tgstation-server	6.11.0 — 6.12.3

References

Advisories & Patches

https://github.com/tgstation/tgstation-server/commit/e7b1189620baaf03c2d23f6e164d07c7c7d87d57 https://github.com/tgstation/tgstation-server/security/advisories/GHSA-rf5r-q276-vrc4

Other References

https://github.com/tgstation/tgstation-server/issues/2064

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2025-21611? +

CVE-2025-21611 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-21611? +

CVE-2025-21611 affects products from tgstation13, specifically: tgstation-server. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-21611? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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