It was discovered that the RMI (Java Remote Method Invocation) server implementation in the JMX (Java Management Extensions) component of OpenJDK did not restrict which classes can be deserialized when deserializing authentication credentials. A remote unauthenticated attacker able to connect to a JMX port could possibly use this flaw trigger deserialization flaws.
Related note in Oracle JDK release notes: New attribute for JMX RMI JRMP servers specifies a list of class names to use when deserializing server credentials A new java attribute has been defined for the environment to allow a JMX RMI JRMP server to specify a list of class names. These names correspond to the closure of class names that are expected by the server when deserializing credentials. For instance, if the expected credentials were a List<string>, then the closure would constitute all the concrete classes that should be expected in the serial form of a list of Strings. By default, this attribute is used only by the default agent with the following: { "[Ljava.lang.String;", "java.lang.String" } Only arrays of Strings and Strings will be accepted when deserializing the credentials. The attribute name is: "jmx.remote.rmi.server.credential.types" The following is an example of a user starting a server with the specified credentials class names: Map<String, Object> env = new HashMap<>(1); env.put ( "jmx.remote.rmi.server.credential.types", new String[]{ String[].class.getName(), String.class.getName() } ); JMXConnectorServer server = JMXConnectorServerFactory.newJMXConnectorServer(url, env, mbeanServer); The new feature should be used by directly specifying: "jmx.remote.rmi.server.credential.types" JDK-8144430 (not public) http://www.oracle.com/technetwork/java/javase/8u91-relnotes-2949462.html http://www.oracle.com/technetwork/java/javaseproducts/documentation/javase7supportreleasenotes-1601161.html#R170_101 http://www.oracle.com/technetwork/java/javase/documentation/overview-156328.html#R160_115
Public now via Oracle Critical Patch Update - April 2016. Fixed in Oracle Java SE 6u115, 7u101, and 8u91. External References: http://www.oracle.com/technetwork/topics/security/cpuapr2016-2881694.html#AppendixJAVA
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Via RHSA-2016:0651 https://rhn.redhat.com/errata/RHSA-2016-0651.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2016:0650 https://rhn.redhat.com/errata/RHSA-2016-0650.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 5 Red Hat Enterprise Linux 7 Via RHSA-2016:0676 https://rhn.redhat.com/errata/RHSA-2016-0676.html
This issue has been addressed in the following products: Oracle Java for Red Hat Enterprise Linux 6 Oracle Java for Red Hat Enterprise Linux 7 Via RHSA-2016:0677 https://rhn.redhat.com/errata/RHSA-2016-0677.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Via RHSA-2016:0675 https://rhn.redhat.com/errata/RHSA-2016-0675.html
This issue has been addressed in the following products: Oracle Java for Red Hat Enterprise Linux 7 Oracle Java for Red Hat Enterprise Linux 5 Oracle Java for Red Hat Enterprise Linux 6 Via RHSA-2016:0679 https://rhn.redhat.com/errata/RHSA-2016-0679.html
This issue has been addressed in the following products: Oracle Java for Red Hat Enterprise Linux 5 Oracle Java for Red Hat Enterprise Linux 6 Oracle Java for Red Hat Enterprise Linux 7 Via RHSA-2016:0678 https://rhn.redhat.com/errata/RHSA-2016-0678.html
OpenJDK8 upstream commit: http://hg.openjdk.java.net/jdk8u/jdk8u/jdk/rev/32f64c19b5fb
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Supplementary Red Hat Enterprise Linux 6 Supplementary Via RHSA-2016:0701 https://rhn.redhat.com/errata/RHSA-2016-0701.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 5 Supplementary Via RHSA-2016:0702 https://rhn.redhat.com/errata/RHSA-2016-0702.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Supplementary Red Hat Enterprise Linux 5 Supplementary Via RHSA-2016:0708 https://rhn.redhat.com/errata/RHSA-2016-0708.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Supplementary Via RHSA-2016:0716 https://rhn.redhat.com/errata/RHSA-2016-0716.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Red Hat Enterprise Linux 5 Red Hat Enterprise Linux 6 Via RHSA-2016:0723 https://rhn.redhat.com/errata/RHSA-2016-0723.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Supplementary Via RHSA-2016:1039 https://rhn.redhat.com/errata/RHSA-2016-1039.html
This issue has been addressed in the following products: Red Hat Satellite 5.6 Red Hat Satellite 5.7 Via RHSA-2016:1430 https://access.redhat.com/errata/RHSA-2016:1430
This issue has been addressed in the following products: Red Hat Satellite 5.6 Red Hat Satellite 5.7 Via RHSA-2017:1216 https://access.redhat.com/errata/RHSA-2017:1216