The Materialis theme for WordPress is vulnerable to limited arbitrary options updates in versions up to, and including, 1.1.24. This is due to missing authorization checks on the companion_disable_popup() function called via an AJAX action. This makes it possible for authenticated attackers, with minimal permissions such as subscribers, to modify any option on the site to a numerical value.
https://themes.trac.wordpress.org/browser/materialis/1.1.20/inc/companion.php#L45