It can be defeated. In fact multiple incomplete ASLR implementations were and are defeated everyday. Even the grsec's implementation has been defeated under cer

It can be defeated. In fact multiple incomplete ASLR implementations were and are defeated everyday. Even the grsec's implementation has been defeated under certain conditions i believe. They just limit attacker's possibilities of getting what he wants. There is no absolute security. Maybe in some kernels like sel4 but they are so small compared to something like linux that it's incomparable.