Abuse Cases

Abuse cases help security testers view the software under test in the same light as attackers do. Abuse cases capture the non-normative behavior of the system. While in [McGraw 04c] abuse cases are described more as a design analysis technique than as a white box testing technique, the same technique can be used to develop innovative and effective test cases mirroring the way attackers would view the system. With access to the source code, a tester is in a better position to quickly see where the weak spots are compared to an outside attacker. The abuse case can also be applied to interactions between components within the system to capture abnormal behavior, should a component misbehave. The technique can also be used to validate design decisions and assumptions. The simplest, most practical method for creating abuse cases is usually through a process of informed brainstorming, involving security, reliability, and subject matter expertise. Known attack patterns form a rich source for developing abuse cases.