glFusion contains a flaw that allows a persistent cross-site scripting (XSS) attack. This flaw exists because the application does not validate the 'address1', 'address2', 'calendar_type', 'city', 'state', 'title', 'url', and 'zipcode' parameters upon submission to the /calendar/index.php script. This may allow an attacker to create a specially crafted request that would execute arbitrary script code in a user's browser within the trust relationship between their browser and the server..