WAPTEC: whitebox analysis of web applications for parameter tampering exploit construction. Parameter tampering attacks are dangerous to a web application whose server fails to replicate the validation of user-supplied data that is performed by the client. Malicious users who circumvent the client can capitalize on the missing server validation. In this paper, we describe WAPTEC, a tool that is designed to automatically identify parameter tampering vulnerabilities and generate exploits by construction to demonstrate those vulnerabilities. WAPTEC involves a new approach to whitebox analysis of the server’s code. We tested WAPTEC on six open source applications and found previously unknown vulnerabilities in every single one of them.