Python Pwntools Hacking: ret2libc GOT & PLT

The video demonstrates solving a 64-bit buffer overflow CTF challenge named "Misfortune" by crafting a Return-to-libc (ROP) payload to bypass NX protection and obtain a shell 0:00.

Key Takeaways:
• The creator identifies a buffer overflow vulnerability that clobbers the RBP register when excessive input causes a segmentation fault 2:15.
• Using a cyclic pattern payload, the attacker determines the buffer overflow offset is 32 bytes 14:41.
• Due to NX protection preventing shellcode execution, the solution requires Return-Oriented Programming (ROP) to chain pop rdi and ret instructions found at specific addresses in the binary 22:31.
• An intermediate payload uses the PLT (puts) and GOT (alarm) to leak the runtime address of the alarm function from libc 28:20.
• By calculating the libc base address from the leak, the attacker locates the system function and /bin/sh string to craft a final payload that spawns a shell 32:40.

Success required combining stack alignment tricks with the ROP chain to successfully execute system("/bin/sh") 37:42.

Sources:

• 2:15 Identifies buffer overflow and segmentation fault
• 14:41 Uses cyclic pattern to find buffer offset
• 22:31 Finds ROP gadgets (pop rdi, ret)
• 28:20 Leaks libc address via GOT/PLT
• 32:40 Calculates libc base