Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Prior to 1.9.6, 1.10.5, 2.0.8, and 2.1.1, @fedify/fedify follows HTTP redirects recursively in its remote document loader and authenticated document loader without enforcing a maximum redirect count or visited-URL loop detection. An attacker who controls a remote ActivityPub key or actor URL can force a server using Fedify to make repeated outbound requests from a single inbound request, leading to resource consumption and denial of service.
This vulnerability is fixed in 1.9.6, 1.10.5, 2.0.8, and 2.1.1.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
References 5
https://github.com/fedify-dev/fedify/security/advisories/GHSA-gm9m-gwc4-hwgp
security-advisories@github.com
https://github.com/fedify-dev/fedify/releases/tag/1.10.5
security-advisories@github.com
https://github.com/fedify-dev/fedify/releases/tag/1.9.6
security-advisories@github.com
https://github.com/fedify-dev/fedify/releases/tag/2.0.8
security-advisories@github.com
https://github.com/fedify-dev/fedify/releases/tag/2.1.1
security-advisories@github.com