zh3r0CTF: Google Source Code

Exploits involved: - LFI - Web shell (PHP) Problem you dont get anything free except the source code. Try to search it and also I never liked to upload my homework in google classroom. Help me hack this website please :) Author : Finch Solution Accessing the link brings us to this page:

The "Classroom" and "Your Work" buttons lead to dead ends. We check the page source code for any leads, and it contains this comment:

This was a (rather guessy) LFI; the source code comment suggesting a parameter called page should be added to the back of URL. After some trial and error, we found adding "?page=upload" takes us to a file upload page:

We upload a PHP webshell file obtained from here: https://github.com/WhiteWinterWolf/wwwolf-php-webshell

After which, we access this webshell by changing page parameter. Now we access webshell PHP page at "web.zh3r0.ml:7777/index.php?page=webshell":

Using `ls -laR` shows there are many fake flag.php files. We use `grep` command to search for the flag using the webshell in the current directory.

Flag: zh3r0{h3y_d1d_y0u_upl04d_php_c0rr3ct1y???_84651320}