Heap spraying is a new security attack that significantly increases the exploitability of existing memory corruption errors in type unsafe applications. With heap spraying, attackers leverage their ability to allocate arbitrary objects in the heap of a type-safe language, such as JavaScript, literally filling the heap with objects that contain dangerous exploit code. In recent years, spraying has been used in many real security exploits, especially in Web browsers.
We propose Nozzle, a runtime monitoring infrastructure that detects attempts by attackers to spray the heap. Nozzle uses lightweight emulation techniques to detect the presence of objects that contain executable code. To reduce false positives, we developed a notion of global “heap health”.
