alexgrad wrote:As the port for the dynamic portal has to be always opened what's the difference to open it on 80/443 or other ports?
Intelligent question!
Answer: Ports 80 & 443 are standard web portals. Script kiddies constantly monitor these ports and collect lists of "available" and share them among groups. You'll notice more and more attempts on more and more known web pages. At first "robots.txt" and the like, but ultimately you'll see attempts to phpMyAdmin "known security risk" pages and ultimately Every Risk (Prior and current) under the sun. And if those attempts meet with Failure or 404 instead of "no response", then you open yourself to being added to yet more attempts. Especially if they find a known login page (sugarCRM? phpMyAdmin?) and fail to log in. Cuz now it's a job for ... Brute Force Scripts! and you end up with a DOS situation due to the brute force attack. Unless they guess a password or find an exploit. Then it's a whole new ballgame.
But on a non-standard port the volume of attack is miniscule at best. There are so many servers out there on the known ports that the non-standards are still being ignored. Plus the Dynamic Good Guys approach didn't expose ANY of the Vicidial or other software: Just a single web page with a special name. Anything else would result in 404. So the only way into the system was to have that link or exploit the 404 page. To date I've not heard of an exploit of the standard 404 page.