This is a technical application security discussion for junior penetration testers or anyone interested in the world of penetration testing. Advanced members of the community are welcome, but the content is geared at newer testers. From Web App to ATM will showcase a penetration test I performed where the only previous work done was web vulnerability scanners that completely missed the iceberg lurking just below the water. In this talk I will cover some "back to basics" of web app security and show real world examples of critical applications exposing these flaws. Unauthenticated APIs, forceful browsing, privilege escalation, and total ownage of ATMs managed by this app are all up for discussion.