Kerio Personal Firewall 4.0.x - Web Filtering Remote Denial of Service
source: https://www.securityfocus.com/bid/10075/info
Kerio Personal Firewall includes Web URI Filtering functionality. A denial of service vulnerability has been reported to affect Kerio Personal Firewall when Web Filtering functionality is enabled. The issue presents itself when Web Filtering procedures handle a URI that contains certain characters.
http://www.example.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=^S^R^S