Version 10.11 of webMethods OneData runs an embedded instance of Azul Zulu Java 11.0.15 which hosts a Java RMI registry (listening on TCP port 2099 by default) and two RMI interfaces (listening on a single, dynamically assigned TCP high port).
Port 2099 serves as a Java Remote Method Invocation (RMI) registry which allows for remotely loading and processing data via RMI interfaces. An unauthenticated attacker with network connectivity to the RMI registry and RMI interface ports can abuse this functionality to instruct the webMethods OneData application to load a malicious serialized Java object as a parameter to one of the available Java methods presented by the RMI interface. Once deserialized on the vulnerable server, the malicious code runs as whichever operating system account is used to run the software, which in most cases is the local System account on Windows.
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Webmethods | Softwareag | 10.11 (including) | 10.11 (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.