In Apache Ignite versions from 2.6.0 and before 2.17.0, configured Class Serialization Filters are ignored for some Ignite endpoints. The vulnerability could be exploited if an attacker manually crafts an Ignite message containing a vulnerable object whose class is present in the Ignite server classpath and sends it to Ignite server endpoints. Deserialization of such a message by the Ignite server may result in the execution of arbitrary code on the Apache Ignite server side.
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
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.