HttpObjectDecoder.java in Netty before 4.1.44 allows a Content-Length header to be accompanied by a second Content-Length header, or by a Transfer-Encoding header.

{
                    "product": "n/a",
                    "vendor": "n/a",
                    "versions": [
                        {
                            "status": "affected",
                            "version": "n/a"
                        }
                    ]
                }