UIUCTF 2021 - PHPFudge (Beginner) Writeup

• Type - Jail
• Name - PHPFudge
• Points - 50

Description

i hate php

http://phpfuck.chal.uiuc.tf

author: arxenix

Writeup

This was a fairly simple challenge to complete. When you navigate to the URL in the description, the page you'll see has this text followed by the output of phpinfo():

<?php
// Flag is inside ./flag.php :)
($x=str_replace("`","",strval($_REQUEST["x"])))&&strlen(count_chars($x,3))<=5?print(eval("return $x;")):show_source(__FILE__)&&phpinfo();

So, I followed the advice of the comment, went to /flag.php, and when you look at the source code, you find the flag!

Flag: uiuctf{pl3as3_n0_m0rE_pHpee}

Original writeup (https://github.com/BYU-CTF-group/writeups-uiuctf/tree/main/phpfudge).