7ffa404e01
|
||
|---|---|---|
| .. | ||
| images | ||
| README.md | ||
README.md
gif
I made a secure php web app where I can upload all my gifs. Some people on the internet told me to run it in a docker container just to protect it from my personal files, but who cares.
About the Challenge
We have been given a plain website that has the functionality to upload a GIF file.
How to Solve?
The first thing I want to test is Unrestricted File Upload vulnerability where we can upload malicious file such as PHP file
At first I tried to upload a PHP file but the server wants us to upload GIF file. So I tried to change the extension file and the MIME type
The server still rejects our request. Now, I am trying to add the GIF magic header. (You can check another file's magic header here)
Yay success, now access the uploaded file on uploads endpoint. To obtain the flag, try to upload below code into the server
GIF89A; <?php system("cat /flag.txt"); ?>
bucket{1_h4t3_PHP}