Better yet: Set your iptables firewall up with ip whitelisting. ONLY allow "known good" IPs to access your system. Then the likelihood of an attack on any port (listed or not) becomes directly related to the people who you've allowed into your system. No hacker in your whitelist = no likelihood of attack.
We also have the Dynamic Good Guys firewall add-on. It includes instructions for whitelisting a Vicibox install as well as the DGG add-on for "easy addition of good IPs":
http://www.viciwiki.com/index.php/DGGSpecifically designed for Vicibox, to keep Vicidial users out of harms way. We published it at this location in 2013.