Contact Form 7 <= 6.0.5 - Order Replay Vulnerability

The Contact Form 7 plugin for WordPress is vulnerable to Order Replay in all versions up to, and including, 6.0.5 via the 'wpcf7_stripe_skip_spam_check' function due to insufficient validation on a user controlled key. This makes it possible for unauthenticated attackers to reuse a single Stripe PaymentIntent for multiple transactions. Only the first transaction is processed via Stripe, but the plugin sends a successful email message for each transaction, which may trick an administrator into fulfilling each order.