RD Station <= 5.2.0 - Cross-Site Request Forgery to Plugin Settings Update

The RD Station plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 5.2.0. This is due to missing or incorrect nonce validation on several functions. This makes it possible for unauthenticated attackers to invoke those functions (including one resulting in settings update), via forged request granted they can trick a site administrator into performing an action such as clicking on a link.