Medium, CVSS 6.9npmAmendedPublished
webfinger.js Blind SSRF Vulnerability
CVE-2025-54590 · GHSA-8xq3-w9fx-74rv
- Affected
- npm webfinger.js <= 2.8.0
- Fixed in
- 2.8.1· Vendor fix available
- Issue
- The lookup function takes a user address for checking accounts as a feature, however, as per the ActivityPub spec (https://www.w3.org/TR/activitypub/#security-considerations), on the security considerations section at B.3, access to Localhost services should be prevented while running in production. The library does not prevent Localhost access (neither does it prevent LAN addresses such as 192.168.x.x) , thus is not safe for use in production by ActivityPub applications. The only check for localhost is done for selecting between HTTP and HTTPS protocols, and it is done by testing for a host that starts with the string “localhost” and ends with a port. Anything else (such as “127.0.0.1” or “localhost:1234/abc”) would not be considered localhost for this test. In addition, the way that the function determines the host, makes it possible to access any path in the host, not only “/.well-known/...” paths: If the address is in the format of a user address (user@host.com), the…
Recommended action: Upgrade to 2.8.1 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.