Fedify is a TypeScript library for building federated server apps powered by ActivityPub. From version 1.2.0 through the affected 1.9, 1.10, 2.0, 2.1, 2.2, and 2.3 maintenance lines, getNodeInfo() fo…

Summary

Fedify is a TypeScript library for building federated server apps powered by ActivityPub. From version 1.2.0 through the affected 1.9, 1.10, 2.0, 2.1, 2.2, and 2.3 maintenance lines, getNodeInfo() follows an attacker-controlled links[].href value from /.well-known/nodeinfo without scheme, redirect, or private-address validation, allowing requests to loopback, link-local, cloud metadata, and private-network services and returning their response bodies. This issue is fixed in versions 1.9.13, 1.1…