Vulnerability CVE-2020-11998

A regression has been introduced in the commit preventing JMX re-bind. By passing an empty environment map to RMIConnectorServer, instead of the map that contains the authentication credentials, it leaves ActiveMQ open to the following attack: https://docs.oracle.com/javase/8/docs/technotes/guides/management/agent.html "A remote client could create a javax.management.loading.MLet MBean and use it to create new MBeans from arbitrary URLs, at least if there is no security manager. In other words, a rogue remote client could make your Java application execute arbitrary code." Mitigation: Upgrade to Apache ActiveMQ 5.15.13