HTTP 403


HTTP 403 is a HTTP status code meaning access to the requested resource is forbidden for some reason. The server understood the request, but will not fulfill it due to client-related issues. IIS defines non standard "sub-status" error codes that provide a more specific reason for responding with the 403 status code.

Specification

HTTP 403 provides a distinct error case from HTTP 401; while HTTP 401 is returned when the client has not authenticated, and implies that a successful response may be returned following valid authentication, HTTP 403 is returned when the client is not permitted access to the resource despite providing authentication such as insufficient permissions of the authenticated account.
Error 403: "The server understood the request, but is refusing to authorise it.", RFC 7231
Error 401: "The request requires user authentication. The response MUST include a WWW-Authenticate header field containing a challenge applicable to the requested resource. The client MAY repeat the request with a suitable Authorisation header field. If the request already included Authorisation credentials, then the 401 response indicates that authorisation has been refused for those credentials." RFC2616
See "403 substatus error codes for IIS" for possible reasons of why the web server is refusing to fulfil the request.
The Apache web server returns 403 Forbidden in response to requests for URL paths that correspond to file system directories when directory listings have been disabled in the server and there is no Directory Index directive to specify an existing file to be returned to the browser. Some administrators configure the Mod proxy extension to Apache to block such requests and this will also return 403 Forbidden. Microsoft IIS responds in the same way when directory listings are denied in that server. In WebDAV, the 403 Forbidden response will be returned by the server if the client issued a PROPFIND request but did not also issue the required Depth header or issued a Depth header of infinity.

Substatus error codes for IIS

The following nonstandard codes are returned by Microsoft's Internet Information Services, and are not officially recognised by IANA.