It is a type of testing in which one will concentrate on the following areas.
Authentication
Direct URL testing
Firewall leakage testingAuthentication: in this type of testing usually one will enter different combinations of usernames and passwords and check whether it is allowing only authorised users or not.
Direct URL: In this type of testing one will enter the direct URL's and try to access the unauthorised pages and check whether they are been accessed or not.
Firewall Leakage: In this type of testing one level of users try to access other level of user pages to check whether firewalls are working properly or not.