CXF supports (via JwtRequestCodeFilter) passing OAuth 2 parameters via a JWT token as opposed to query parameters (see: The OAuth 2.0 Authorization Framework: JWT Secured Authorization Request (JAR)). Instead of sending a JWT token as a request parameter, the spec also supports specifying a URI from which to retrieve a JWT token from via the request_uri parameter. CXF was not validating the request_uri parameter (apart from ensuring it uses https) and was making a REST request to the parameter in the request to retrieve a token. This means that CXF was vulnerable to DDos attacks on the authorization server, as specified in section 10.4.1 of the spec. This issue affects Apache CXF versions prior to 3.4.3; Apache CXF versions prior to 3.3.10.
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Cxf | Apache | * | 3.3.10 (excluding) |
| Cxf | Apache | 3.4.0 (including) | 3.4.3 (excluding) |