XWiki Platform CSRF remote code execution through scheduler job's document reference

XWiki Platform is a generic wiki platform. Starting in version 3.1 and prior to versions 4.10.19, 15.5.4, and 15.10-rc-1, by creating a document with a special crafted documented reference and an `XWiki.SchedulerJobClass` XObject, it is possible to execute arbitrary code on the server whenever an admin visits the scheduler page or the scheduler page is referenced, e.g., via an image in a comment on a page in the wiki. The vulnerability has been fixed in XWiki 14.10.19, 15.5.5, and 15.9. As a workaround, apply the patch manually by modifying the `Scheduler.WebHome` page.