Cross-site scripting (XSS) vulnerability in Sitecore CMS before 7.0 Update-4 (rev. 140120) allows remote attackers to inject arbitrary web script or HTML via the xmlcontrol parameter to the default URI. NOTE: some of these details are obtained from third party information.
https://exchange.xforce.ibmcloud.com/vulnerabilities/90833
http://www.securityfocus.com/archive/1/530901/100/0/threaded
http://sitecorekh.blogspot.dk/2014/01/sitecore-releases-70-update-4-rev-140120.html