In the Golang Chi web framework, the ClientIPFromXFF middleware skips any X-Forwarded-For entry in a configured trusted CIDR but never verifies that the direct TCP peer in http.Request.RemoteAddr belongs to that CIDR. A client that can reach the Go server directly can therefore append a trusted-looking proxy address and choose the client IP returned by middleware.GetClientIP.
This issue affects chi before 5.4.0.
Weakness
The product has two different sources of the same data or information, but it uses the source that has less support for verification, is less trusted, or is less resistant to attack.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/141.html
- https://cwe.mitre.org/data/definitions/142.html
- https://cwe.mitre.org/data/definitions/73.html
- https://cwe.mitre.org/data/definitions/76.html
- https://cwe.mitre.org/data/definitions/85.html