XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. In affected versions there is no protection against URL redirection to untrusted sites, in particular some well known parameters (xredirect) can be used to perform url redirections. This problem has been patched in XWiki 12.10.7 and XWiki 13.3RC1. Users are advised to update. There are no known workarounds for this issue.