WP Users Media <= 4.2.3 - Cross-Site Request Forgery in wpusme_save_settings

Description

The WP Users Media plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 4.2.3. This is due to missing or incorrect nonce validation on the wpusme_save_settings function. This makes it possible for unauthenticated attackers to modify plugin settings via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.