We are given an ELF executable file, guestbook and a service for the executable. Our goal is
to spawn a shell from the service. Decompiling guestbook with IDA will yield this C pseudo-code:
int __cdecl main(int argc, const char **argv, const char **envp)
{
char s; // [sp+0h] [bp-98h]@16 …We are given two files: one is simple.py, which used to do an encryption, and pubkey.txt,
which is the generated public key when encrypting with simple.py. Here's the content of
simpe.py.
from Crypto.Util.number import *
import random
# from flag import FLAG
def generate(nbits):
p …We are given a file, hack.py, which looks as follows.
from Crypto.Util.number import *
from hashlib import md5
flag = "XXX"
assert len(flag) == 4
pad = bytes_to_long(md5(flag).digest())
hack = 0
for char in flag:
hack+= pad
hack*= ord(char)
print hack
print pad
print hack % pad
#hack …