Stack Smashing Protector: Difference between revisions

The '''Stack Smashing Protector''' ('''SSP''') compiler feature helps detect stack buffer overrun by aborting if a secret value on the stack is changed. This serves a dual purpose in making the occurrence of such bugs visible and as exploit mitigation against return-oriented programming. SSP merely detects stack buffer overruns, they are not prevented. The detection can be beaten by preparing the input such that the stack canary is overwritten with the correct value and thus does not offer perfect protection. The stack canary is native word sized and if chosen randomly, an attacker will have to guess the right value among 2^32 or 2^64 combinations (and revealing the bug if the guess is wrong), or resort to clever means of determining it.