CVE-2025-23221: Fedify has an Infinite loop and Blind SSRF found inside the Webfinger mechanism
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.
Classification
CVE ID: CVE-2025-23221
CVSS Base Severity: MEDIUM
CVSS Base Score: 5.4
Affected Products
Vendor: dahlia
Product: fedify
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.06% (probability of being exploited)
EPSS Percentile: 29.09% (scored less or equal to compared to others)
EPSS Date: 2025-02-18 (when was this score calculated)
References
https://github.com/dahlia/fedify/security/advisories/GHSA-c59p-wq67-24wxhttps://github.com/dahlia/fedify/commit/8be3c2038eebf4ae12481683a1e809b314be3151
https://github.com/dahlia/fedify/commit/c505eb82fcd6b5b17174c6659c29721bc801ab9a
https://github.com/dahlia/fedify/commit/e921134dd5097586e4563ea80b9e8d1b5460a645