XWiki Platform vulnerable to CSRF privilege escalation/RCE via the create action

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. The create action is vulnerable to a CSRF attack, allowing script and thus remote code execution when targeting a user with script/programming right, thus compromising the confidentiality, integrity and availability of the whole XWiki installation. When a user with script right views this image and a log message `ERROR foo - Script executed!` appears in the log, the XWiki installation is vulnerable. This has been patched in XWiki 14.10.9 and 15.4RC1 by requiring a CSRF token for the actual page creation.