In Apache Dubbo, users may choose to use the Hessian protocol. The Hessian protocol is implemented on top of HTTP and passes the body of a POST request directly to a HessianSkeleton: New HessianSkeleton are created without any configuration of the serialization factory and therefore without applying the dubbo properties for applying allowed or blocked type lists. In addition, the generic service is always exposed and therefore attackers do not need to figure out a valid service/method name pair. This is fixed in 2.7.13, 2.6.10.1
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Dubbo | Apache | 2.7.0 (including) | 2.7.12 (including) |
| Dubbo | Apache | 3.0.0 (including) | 3.0.1 (including) |
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.