CVE-2025-23221: SSRF (CVSS 5.4)

Description

Fedify is a TypeScript library for building federated server apps powered by ActivityPub and other standards. This vulnerability allows a user to maneuver the Webfinger mechanism to perform a GET request to any internal resource on any Host, Port, URL combination regardless of present security mechanisms, and forcing the victim’s server into an infinite loop causing Denial of Service. Moreover, this issue can also be maneuvered into performing a Blind SSRF attack. This vulnerability is fixed in 1.0.14, 1.1.11, 1.2.11, and 1.3.4.

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CVSS v3.1 Score

5.4

MEDIUM

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

Weakness Type (CWE)

CWE-835 CWE-835

CWE-918 Server-Side Request Forgery (SSRF)

References

Other References

https://github.com/dahlia/fedify/commit/8be3c2038eebf4ae12481683a1e809b314be3151 https://github.com/dahlia/fedify/commit/c505eb82fcd6b5b17174c6659c29721bc801ab9a https://github.com/dahlia/fedify/commit/e921134dd5097586e4563ea80b9e8d1b5460a645 https://github.com/dahlia/fedify/security/advisories/GHSA-c59p-wq67-24wx

Frequently Asked Questions

What is CVE-2025-23221? +

Fedify is a TypeScript library for building federated server apps powered by ActivityPub and other standards. This vulnerability allows a user to maneuver the Webfinger mechanism to perform a GET request to any internal resource on any Host, Port, URL combination regardless of present security mechanisms, and forcing the victim’s server into an infinite loop causing Denial of Service. Moreover, this issue can also be maneuvered into performing a Blind SSRF attack. This vulnerability is fixed in 1.0.14, 1.1.11, 1.2.11, and 1.3.4. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2025-23221? +

CVE-2025-23221 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

How do I check if I'm vulnerable to CVE-2025-23221? +

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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