In the process of hacking a web application, attackers manipulate the HTTP requests to subvert...

In the process of hacking a web application, attackers manipulate the HTTP requests to subvert the application authorization schemes by modifying input fields that relate to the user ID, username, access group, cost, file names, file identifiers, etc.

They first access the web application using a low privileged account and then escalate privileges to access protected resources. What attack has been carried out?