PHP iCalendar 1.1/2.x - 'getdate' Cross-Site Scripting

source: https://www.securityfocus.com/bid/21792/info
     
PHP icalendar is prone to multiple cross-site scripting vulnerabilities because the application fails to properly sanitize user-supplied input. 
     
An attacker may leverage these issues to have arbitrary script code execute in the browser of an unsuspecting user. This may help the attacker steal cookie-based authentication credentials and launch other attacks.
     
http://www.example.com/phpicalendar/rss/index.php?cal=Home,US+Holidays,Work &getdate=20061225"><script>alert()</script>