PopupAlly < 2.1.1 - Cross-Site Request Forgery via optin_submit_callback

Description The PopupAlly plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.1.0. This is due to missing or incorrect nonce validation on the ‘optin_submit_callback’ function. This makes it possible for unauthenticated attackers to opt in subscribers via a forged request granted they can trick a victim into performing an action such as clicking on a link.