Werkzeug < 2.1.0 - HTTP Request Smuggling via Crafted Request Body
Improper parsing of HTTP requests in Pallets Werkzeug v2.1.0 and below allows attackers to perform HTTP Request Smuggling using a crafted HTTP request with multiple requests included inside the body. NOTE: the vendor's position is that this behavior can only occur in unsupported configurations involving development mode and an HTTP server from outside the Werkzeug project