The Simple User Capabilities plugin for WordPress is vulnerable to Privilege Escalation due to a missing capability check on the suc_submit_capabilities() function in all versions up to, and including, 1.0. This makes it possible for unauthenticated attackers to elevate the role of any user account to administrator.
https://wordpress.org/plugins/simple-user-capabilities/
https://plugins.svn.wordpress.org/simple-user-capabilities/tags/1.0/user_access.php