The host is installed with Apache Tomcat 8.5.0 through 8.5.75 or 9.0.0.M1 through 9.0.20 and is prone to an improper resource shutdown vulnerability. A flaw is present in application, which fails to handle a WebSocket message sent concurrently with the WebSocket connection closed. Successful exploitation allows attackers to perform subsequent connections using the pooled object concurrently which could result in data being returned to the wrong use and/or other errors.