What happened
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, 1.10.12, 2.0.22, 2.1.18, 2.2.7, and 2.3.2.
Affected versions
fedify: >= 1.2.0, < 1.9.13; >= 1.10.0, < 1.10.12; >= 2.0.0, < 2.0.22; >= 2.1.0, < 2.1.18; >= 2.2.0, < 2.2.7; >= 2.3.0, < 2.3.2 Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.