Web services assessment can begin with a corporate name or some other such bit of information. This simple hint offers a wealth of information that needs to be unearthed. Focus first on locating single or multiple access points for a particular corporate. The methodology, which includes web services footprinting, discovery and search, is described in another paper (http://packetstormsecurity.org/papers/web/Defense_using_mod_security.pdf). Once an access point for a web service is uncovered, the next obvious step is to extract information from it.
Web services are deployed to invoke remote calls over HTTP/HTTPS. To make calls such as these, requires that information about the calls be shared with the end client. In the past, during the days of CORBA, developers used to share IDL (Interface Definition Language) files providing the required information over the network. Now, in the days of web services this has changed to WSDL (Web Services Definition Language). WSDL is a major source for information and can help in the enumeration process. We shall go over the enumeration process in subsequent sections.