MailChimp Forms by MailMunch < 3.2.2 - Cross-Site Request Forgery

Description

The MailChimp Forms by MailMunch plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 3.2.1. This is due to missing or incorrect nonce validation on the integrate case. This makes it possible for unauthenticated attackers to update the plugin's access token via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.