Cross-site scripting (XSS) vulnerability in Vaadin before 6.4.9 allows remote attackers to inject arbitrary web script or HTML via unknown vectors related to the index page.
https://exchange.xforce.ibmcloud.com/vulnerabilities/64626
http://www.securityfocus.com/bid/45779
http://vaadin.com/download/release/6.4/6.4.9/release-notes.html