The Gravity SMTP plugin for WordPress is vulnerable to Missing Authorization in versions up to, and including, 2.1.4. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to uninstall and deactivate the plugin and delete plugin options. NOTE: This vulnerability is also exploitable via a Cross-Site Request Forgery vector.
https://www.gravityforms.com/brand-new-release-gravity-smtp-2-1-5/