Describe CVE-2021-44911.
What is CVE-2021-44911?
XE before 1.11.6 is vulnerable to Unrestricted file upload via modules/menu/menu.admin.controller.php. When uploading the Mouse over button and When selected button, there is no restriction on the file suffix, which leads to any file uploading to the files directory. Since .htaccess only restricts the PHP type, uploading HTML-type files leads to stored XSS vulnerabilities..