Exploit Dev — Shellcode

ret2win only worked because a win() existed. When it does not, you bring your own code. We hand-roll a null-free execve("/bin/sh") in assembly, understand the execve syscall setup, assemble it to bytes, and tackle the bad-character problem — why 0x00 and 0x0a truncate your payload and how to rewrite around it. Then we generate shellcode fast with pwntools shellcraft and msfvenom, and deliver it with ret2shellcode plus a NOP sled.