In-Portal might be vulnerable to Host header injections due following code in the
SERVER_NAME constant is used to build absolute urls on the website. This way if attacker sends fake Host header then all links would lead to fake domain instead of ours (even though page url in browser would be from our domain).
Forcing to use domain from command line might solve the problem, but not for websites where site domains are used. There you can set wildcards for domain matching and you can't check even them in the startup.php because no database connection is created yet.