Contact Form 7 – PayPal & Stripe Add-on <= 2.1 is vulnerable to Cross-Site Request Forgery to Settings Update vulnerability

The Easy PayPal & Stripe Buy Now Button plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.8.3 and in Contact Form 7 – PayPal & Stripe Add-on all versions up to, and including 2.1. This is due to missing or incorrect nonce validation on the 'wpecpp_stripe_connect_completion' function. This makes it possible for unauthenticated attackers to modify the plugins settings and chance the stripe connection via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.