Apache ActiveMQ: Insufficient API restrictions on Jolokia allow authenticated users to perform RCE

Summary

Once an user is authenticated on Jolokia, he can potentially trigger arbitrary code execution.  In details, in ActiveMQ configurations, jetty allows org.jolokia.http.AgentServlet to handler request to /api/jolokia org.jolokia.http.HttpRequestHandler#handlePostRequest is able to create JmxRequest through JSONObject. And calls to org.jolokia.http.HttpRequestHandler#executeRequest. Into deeper calling stacks, org.jolokia.handler.ExecHandler#doHandleRequest can be invoked through refection. This could lead to RCE through via various mbeans. One example is unrestricted deserialization in jdk.management.jfr.FlightRecorderMXBeanImpl which exists on Java version above 11. 1 Call newRecording. 2 Call setConfiguration. And a webshell data hides in it. 3 Call startRecording. 4 Call copyTo method. The webshell will be written to a .jsp file. The mitigation is to restrict (by default) the actions authorized on Jolokia, or disable Jolokia. A more restrictive Jolokia configuration has been defined in default ActiveMQ distribution. We encourage users to upgrade to ActiveMQ distributions version including updated Jolokia configuration: 5.16.6, 5.17.4, 5.18.0, 6.0.0.