BlueSnap Payment Gateway for WooCommerce <=3.4.0 - IPN Authorization Bypass

BlueSnap Payment Gateway for WooCommerce = 3.4.0 validates its unauthenticated IPN webhook using WooCommerce's client-IP geolocation, which trusts spoofed forwarding headers instead of requiring a webhook signature. Version 3.4.1 replaces the IP check with HMAC-SHA256 security headers. This...