Change default values for Network-->Firewall settings
Upon install of Operator, the default settings for Network --> Firewall appear to appears to allow access from "All IP Addresses". These default settings appear to conflict with what's recommended in Kerio KB article: http://kb.kerio.com/product/kerio-operator/server-configuration-kerio-operator/securing-kerio-operator-819.html which recommends that Phone Provisioning, CRM Integration, and SNMP Monitoring all be restricted to internal network IP addresses. My recommendation is that those 3 options be set to "Local Clients" by default.
By default, only webserver and SIP are available to the public. Other protocols are open to local ip addresses.