Please view the original advisory/exploit here.
The Joomla component com_jsupport suffers from a critical XSS vulnerability:
The component allows you to create and submit tickets. The tickets can be viewed on the website and in the admin panel. It is possible to inject arbitrary HTML and JS/VBS code into the title field of the ticket. If someone else views the ticket list, the code gets executed in the visitor's browser. This vulnerability is considered as critical since the tickets are also displayed in the administrator backend of Joomla. As soon as a user with extended priviledges views the ticket list in the backend, the code gets executed and damage can be caused. Example code for the ticket title field: "><IMG """><SCRIPT>alert("XSS")</SCRIPT>