CVE-2019-12418

A privilege escalation flaw was found in Tomcat when the JMX Remote Lifecycle Listener was enabled. A local attacker without access to the Tomcat process or configuration files could be able to manipulate the RMI registry to perform a man-in-the-middle attack. The attacker could then capture user names and passwords used to access the JMX interface and gain complete control over the Tomcat instance.

Mitigation

Disable JMX Remote if monitoring is only needed locally and there is no need to monitor Tomcat remotely. If JMX Remote is required and cannot be disabled, then use the built-in remote JMX facilities provided by the JVM.
Please note that JMX Remote Lifecycle Listener is now deprecated and may be removed from both Tomcat 7 [1] and Tomcat 9 [2] after 2020-12-31.

[1] <https://tomcat.apache.org/tomcat-7.0-doc/config/listeners.html#Deprecated_Implementations&gt;
[2] <https://tomcat.apache.org/tomcat-9.0-doc/config/listeners.html#Deprecated_Implementations&gt;