Simple SEO <= 2.0.25 - Cross-Site Request Forgery via multiple admin_post functions

The Simple SEO plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.25. This is due to missing or incorrect nonce validation on multiple admin_post functions. This makes it possible for unauthenticated attackers to import SEO content from other plugins as well as generate and delete sitemaps via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.