Traditional vulnerabilities like SQL Injection, buffer overflows, etc, have well established techniques for discovery and prevention. On the other hand, logic flaws are incredibly diverse and often unique to the specific application or business organization. Because of this, logic flaws have taken on a near mythical status. In the myth, logic flaws are nearly impossible to find until the elite of the elite hackers launch an attack to completely own the application. The reality is far different; logic flaws are not the complex nightmare that many have made them out to be. This presentation will use real-world examples to show how logic flaws are typically introduced into an application, how they can be consistently detected during testing, and how they can be prevented during development. Instead of hoping for magic, repeatable processes will be outlined for each of those items. This will prove beneficial to anyone responsible for application security: programmers, architects, managers, and pen testers.
David Byrne has worked in information security for almost a decade. Currently, he is a consultant in Trustwave's Application Penetration Testing group. Before Trustwave, David was the Security Architect at Dish Network. In 2006, he started the Denver chapter of OWASP. In 2008, he released Grendel (grendel-scan.com), an open source web application security scanner. David has presented at a number of security events including DEFCON, Black Hat, Toorcon, FROC, and the SANS penetration testing summit. Charles Henderson has been in the security industry for over 15 years and manages the Application Penetration Testing and Code Review Practice at Trustwave. He has specialized in application security testing and application security assessment throughout his career but has also worked in physical security testing and network security testing.