It was found that the Apache ActiveMQ client before 5.14.5 exposed a remote shutdown command in the ActiveMQConnection class. An attacker logged into a compromised broker could use this flaw to achieve denial of service on a connected client.
It was discovered that the hawtio servlet 1.4 uses a single HttpClient instance to proxy requests with a persistent cookie store (cookies are stored locally and are not passed between the client and the end URL) which means all clients using that proxy are sharing the same cookies.