Description
Fedify is a TypeScript library for building federated server apps powered by ActivityPub. In versions below 1.3.20, 1.4.0-dev.585 through 1.4.12, 1.5.0-dev.636 through 1.5.4, 1.6.0-dev.754 through 1.6.7, 1.7.0-pr.251.885 through 1.7.8 and 1.8.0-dev.909 through 1.8.4, an authentication bypass vulnerability allows any unauthenticated attacker to impersonate any ActivityPub actor by sending forged activities signed with their own keys. Activities are processed before verifying the signing key belongs to the claimed actor, enabling complete actor impersonation across all Fedify instances. This is fixed in versions 1.3.20, 1.4.13, 1.5.5, 1.6.8, 1.7.9 and 1.8.5.
CVSS breakdown
CVSS 4.0
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality (Vulnerable System)
None
Integrity (Vulnerable System)
High
Availability (Vulnerable System)
None
Confidentiality (Subsequent System)
None
Integrity (Subsequent System)
None
Availability (Subsequent System)
None
Affected products
- fedify-dev / fedify< 1.3.20 – < 1.3.20
- fedify-dev / fedify>= 1.4.0-dev.585, < 1.4.13 – >= 1.4.0-dev.585, < 1.4.13
- fedify-dev / fedify>= 1.5.0-dev.636, < 1.5.5 – >= 1.5.0-dev.636, < 1.5.5
- fedify-dev / fedify>= 1.6.0-dev.754, < 1.6.8 – >= 1.6.0-dev.754, < 1.6.8
- fedify-dev / fedify>= 1.7.0-pr.251.885, < 1.7.9 – >= 1.7.0-pr.251.885, < 1.7.9
- fedify-dev / fedify>= 1.8.0-dev.909, < 1.8.5 – >= 1.8.0-dev.909, < 1.8.5