The Business Essentials for Contact Form 7 plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'gateway' Form Field in all versions up to, and including, 1.2.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires the Payments module to be enabled and a form to be configured to accept both PayPal and Stripe as payment gateways.