Apache James server version 3.7.3 and earlier provides a JMX management service without authentication by default. This allows privilege escalation by a malicious local user. Administrators are advised to disable JMX, or set up a JMX password. Note that version 3.7.4 onward will set up a JMX password automatically for Guice users.
https://lists.apache.org/thread/2z44rg93pflbjhvbwy3xtz505bx41cbs