PayPal Express Checkout <= 2.1.2 - Cross-Site Request Forgery

Description

The PayPal Express Checkout plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.1.2. This is due to missing or incorrect nonce validation on a function. This makes it possible for unauthenticated attackers to perform an unauthorized action granted they can trick a site administrator into performing an action such as clicking on a link.