Class 08 · KP 01 / 20

The Modern Defense Stack

In Class 03—05 we saw classic stack smashing: overwrite a return address, jump to shellcode on the stack.
Modern systems break that in two independent ways:
NX (No-eXecute / DEP): the stack and heap are not executable. Injected shellcode simply will not run.
ASLR: the addresses of the stack, heap, and shared libraries (libc) are randomized on every run. You do not know where anything is.
A single memory-corruption bug rarely buys you a shell anymore. You must chain primitives.

Key Takeaway

Real exploits are pipelines: first defeat ASLR, then hijack control flow. We study the chain to understand how to break it.