I don't have anything to add but, may I ask a question?

And, go easy on me. I'm not a programer.

Using your example, a cracker would put 2k of garble followed by Xk of specific code (whatever code he wanted) into the buffer.

If the overflow happened to fall into the instruction stack, his code would eventually be executed.

If his code fell into an area of memory that was not being used by the stack, it would do nothing untill it was eventually overwritten by code using that memory location.

Am I close? And, like I said, it's 4AM and I'm no programer.