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Loop with Unreachable Exit Condition ('Infinite Loop')

CVE-2025-23221

Medium
5.4/10

Summary

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 issue affects the package @fedify/fedify versions through 1.0.13, 1.1.0-dev.421 through 1.1.10, 1.2.0-dev.450 through 1.2.10, 1.3.0-dev.477 through 1.3.3, and 1.4.0-dev.585 through 1.4.0-dev.599.

  • HIGH
  • NETWORK
  • NONE
  • CHANGED
  • NONE
  • NONE
  • LOW
  • LOW

CWE-835 - Loop with Unreachable Exit Condition

Loops with multiple exits and flags detract from the quality of an application. They tend to make control structures difficult to understand, and introduce the risk of non-termination and other structural problems. The vulnerability “loop with unreachable exit condition” enables attackers to exploit this flaw, leading to denial of service.

References

Advisory Timeline

  • Published