CVE-2025-23221

Infinite loop and Blind SSRF found inside the Webfinger mechanism in @fedify/fedify

1. Implement a limiting stop condition for the endless loop to prevent infinite loops.
2. Validate the scheme while performing a manual redirection handler.
3. For each web resource (for the lookupWebFinger function and also URLs found on the “Location” header inside the loop) use the “validatePublicUrl” function to verify that it is not targeting a local resource.

Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.

CVE-2025-23221 has a CVSS score of 5.4 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.0.14, 1.1.11, 1.2.11, 1.3.4); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-23221? CVE-2025-23221 is a medium-severity server-side request forgery (SSRF) vulnerability in @fedify/fedify (npm), affecting versions = 1.0.13. It is fixed in 1.0.14, 1.1.11, 1.2.11, 1.3.4. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
2. How severe is CVE-2025-23221? CVE-2025-23221 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of @fedify/fedify are affected by CVE-2025-23221? @fedify/fedify (npm) versions = 1.0.13 is affected.
4. Is there a fix for CVE-2025-23221? Yes. CVE-2025-23221 is fixed in 1.0.14, 1.1.11, 1.2.11, 1.3.4. Upgrade to this version or later.
5. Is CVE-2025-23221 exploitable, and should I be worried? Whether CVE-2025-23221 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-23221 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-23221?
   • Upgrade @fedify/fedify to 1.0.14 or later
   • Upgrade @fedify/fedify to 1.1.11 or later
   • Upgrade @fedify/fedify to 1.2.11 or later
   • Upgrade @fedify/fedify to 1.3.4 or later