XWiki Platform Attachment UI provides a macro to easily upload and select attachments for XWiki Platform, a generic wiki platform. Starting with version 14.0-rc-1 and prior to 14.4-rc-1, it's possible to store JavaScript in an attachment name, which will be executed by anyone trying to move the corresponding attachment. This issue has been patched in XWiki 14.4-rc-1. As a workaround, one may copy "moveStep1.vm" to "webapp/xwiki/templates/moveStep1.vm" and replace vulnerable code with code from the patch.