solution.md

Challenge

I heard this is the coolest site for cowboys and can you find a way in?

Setup

Website: https://web-cowboy-world-54f063db.chal-2021.duc.tf

Solution

Upon visiting the website, we are greeted with a login page containing a user and password field. /robots.txt (text file used to indicate to search engines which file(s) or directory/directories not to include) includes an entry for /sad.eml. When we visit that path on the website, an email file is downloaded. We can view its contents with a text editor and find this string:

thats why a 'sadcowboy' is only allowed to go into our website

This indicates that only the username sadcowboy allows access to the website. Now, for the password field, upon entering a ', an internal server error is raised. This indicates a SQL vulnerability due to unescaped characters, which we can exploit with SQL injection. One common payload is 'OR '1'='1, which works and allows us to login.
Flag: DUCTF{haww_yeeee_downunderctf?}