In computer security, heap spraying is a technique used in exploits to facilitate arbitrary code execution. The term is also used to describe the part of the source code of an exploit that implements this technique. In general, code that sprays the heap attempts to put a certain sequence of bytes at a predetermined location in the memory of a target process by having it allocate (large) blocks on the process' heap and fill the bytes in these blocks with the right values. They commonly take advantage from the fact that these heap blocks will roughly be in the same location every time the heap spray is run.
http://en.wikipedia.org/wiki/Heap_spraying
