Under very specific circumstances (see Required configuration section below), a privileged user is able to cause arbitrary code to be executed which may cause further disruption to services. This is specific to applications written in C#. This affects all MongoDB .NET/C# Driver versions prior to and including v2.18.0
Following configuration must be true for the vulnerability to be applicable: * Application must written in C# taking arbitrary data from users and serializing data using _t without any validation AND
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| C#_driver | Mongodb | * | 2.19.0 (excluding) |
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.