_layouts/Upload.aspx in the Documents module in Microsoft SharePoint before 2010 uses URLs with the same hostname and port number for a web site's primary files and individual users' uploaded files (aka attachments), which allows remote authenticated users to leverage same-origin relationships and conduct cross-site scripting (XSS) attacks by uploading TXT files, a related issue to CVE-2008-5026. NOTE: the vendor disputes the significance of this issue, because cross-domain isolation can be implemented when needed.