The host is installed with Apache Tomcat 11.0.0-M1 through 11.0.0-M11, 10.1.0-M1 through 10.1.13, 9.0.0-M1 through 9.0.80 or 8.5.0 through 8.5.93 and is prone to an improper input validation vulnerability. A flaw is present in the application, which fails to properly parse HTTP trailer headers. Successful exploitation could cause Tomcat to treat a single request as multiple requests leading to the possibility of request smuggling when behind a reverse proxy.