YayMail < 4.3.3 - Shop Manager+ Arbitrary Options Update

Description

The plugin is vulnerable to unauthorized modification of data that can lead to privilege escalation due to a missing capability check on the `yaymail_import_state` AJAX action. This makes it possible for authenticated attackers, with Shop Manager-level access and above, to update arbitrary options on the WordPress site. This can be leveraged to update the default role for registration to administrator and enable user registration for attackers to gain administrative user access to a vulnerable site.