Marker.io <= 1.1.8 is vulnerable to Cross Site Request Forgery (CSRF) vulnerability

The Marker.io plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 1.1.8. This is due to missing or incorrect nonce validation on the markerio_save_option() function. This makes it possible for unauthenticated attackers to update the plugin's settings via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.