Description

ORY Fosite is a security first OAuth2 & OpenID Connect framework for Go. In Fosite before version 0.34.1, the OAuth 2.0 Client's registered redirect URLs and the redirect URL provided at the OAuth2 Authorization Endpoint where compared using strings.ToLower while they should have been compared with a simple string match. This allows an attacker to register a client with allowed redirect URL https://example.com/callback. Then perform an OAuth2 flow and requesting redirect URL https://example.com/CALLBACK. Instead of an error (invalid redirect URL), the browser is redirected to https://example.com/CALLBACK with a potentially successful OAuth2 response, depending on the state of the overall OAuth2 flow (the user might still deny the request for example). This vulnerability has been patched in ORY Fosite v0.34.1.

Weaknesses 3

Affected Products 1

References 2

• github.com https://github.com/ory/fosite/commit/cdee51ebe721bfc8acca0fd0b86b030ca70867bf
  PatchThird Party Advisory
• github.com https://github.com/ory/fosite/security/advisories/GHSA-grfp-q2mm-hfp6
  Third Party Advisory

Remediation

• github.com https://github.com/ory/fosite/commit/cdee51ebe721bfc8acca0fd0b86b030ca70867bf
  PatchThird Party Advisory