Can you gain admin access to this site?
http://easyauth-afee0e67.ctf.bsidessf.net
easyauth.php

Looking at the php script, we see that the only authentication for the admin account is if the username=administrator. So, log-in as guest to get a valid cookie, then use burp to change the username to administrator.

burp screenshot

After sending the modified request, the flag was revealed.

adminpanel screenshot

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