HTTP Request/Response Smuggling

gevent is vulnerable to HTTP Request/Response Smuggling. The vulnerability is caused by a missing validation check on trailers in processing of chunked requests in the WSGI application on keep-alive connections. This can lead to an attacker carefully crafting invalid trailers in chunked requests that might appear as two requests to gevent.pywsgi and the embedded second request can bypass the filtering of incoming requests based on paths or header fields leading to privilege escalation.