407

Proxy Authentication Required

This code is similar to 401, and here the server expects the client requests to be authenticated by a proxy, i.e. the requests must have a valid `Proxy-Authenticate` header to be served. Failed requests can try again after authentication from the proxy.

Use Case

A malicious user is trying to fetch information about another user from a server, but the server rejects the requests because the request does not have the authorization credentials which are provided by the proxy to make such requests.