The Pulsating Chat Button plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.3.6. This is due to missing or incorrect nonce validation on the amin_chat_button_settings_page() function. This makes it possible for unauthenticated attackers to update settings and inject malicious web scripts via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.