Apache Karaf allows monitoring of applications and the Java runtime by using the Java Management Extensions (JMX). JMX is a Java RMI based technology that relies on Java serialized objects for client server communication. Whereas the default JMX implementation is hardened against unauthenticated deserialization attacks, the implementation used by Apache Karaf is not protected against this kind of attack. The impact of Java deserialization vulnerabilities strongly depends on the classes that are available within the targets class path. Generally speaking, deserialization of untrusted data does always represent a high security risk and should be prevented. The risk is low as, by default, Karaf uses a limited set of classes in the JMX server class path. It depends of system scoped classes (e.g. jar in the lib folder).
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Karaf | Apache | * | 4.3.6 (excluding) |
| Red Hat Fuse 7.11 | RedHat | karaf | * |
It is often convenient to serialize objects for communication or to save them for later use. However, deserialized data or code can often be modified without using the provided accessor functions if it does not use cryptography to protect itself. Furthermore, any cryptography would still be client-side security – which is a dangerous security assumption. Data that is untrusted can not be trusted to be well-formed. When developers place no restrictions on “gadget chains,” or series of instances and method invocations that can self-execute during the deserialization process (i.e., before the object is returned to the caller), it is sometimes possible for attackers to leverage them to perform unauthorized actions, like generating a shell.