XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Simple users can create global SSX/JSX without specific rights: in theory only users with Programming Rights should be allowed to create SSX or JSX that are executed everywhere on a wiki. But a bug allow anyone with edit rights to actually create those. This issue has been patched in XWiki 13.10-rc-1, 12.10.11 and 13.4.6. There's no easy workaround for this issue, administrators should upgrade their wiki.

In XWiki before versions 11.10.5 or 12.2.1, any user with SCRIPT right (EDIT right before XWiki 7.4) can gain access to the application server Servlet context which contains tools allowing to instantiate arbitrary Java objects and invoke methods that may lead to arbitrary code execution. The only workaround is to give SCRIPT right only to trusted users.