Apache Tomcat Inconsistent Interpretation of HTTP Requests (HTTP Request Smuggling) Vulnerability - CVE-2021-33037

Apache Tomcat 10.0.0-M1 to 10.0.6 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request smuggling when used with a reverse proxy. Specifically: - Tomcat incorrectly ignored the transfer encoding header if the client declared it would only accept an HTTP/1.0 response - Tomcat honoured the identify encoding and - Tomcat did not ensure that if present the chunked encoding was the final encoding.