RestrictedPicklers

RestrictedPicklers is a term that has emerged in certain online communities, particularly those discussing serialized data formats and security concerns. It refers to a potential vulnerability or an intentional security measure related to the deserialization of data in programming languages that support pickling. Pickling is a process of serializing and de-serializing Python object structures.

The core issue with restricted pickling lies in the potential for malicious code execution. When an application deserializes data from an untrusted source using a standard pickling mechanism, it can be tricked into executing arbitrary code. This is because pickle can serialize not just data, but also instructions for how to reconstruct objects, which can include functions or methods that, when executed during deserialization, perform harmful actions.

In response to these risks, developers may implement "restricted pickling." This involves creating custom pickling or unpickling functions that explicitly limit what types of objects or functions can be deserialized. The goal is to create a whitelist or a set of permitted actions, thereby preventing the execution of malicious payloads. For instance, a restricted pickler might only allow the deserialization of simple data types like strings, integers, or lists, while explicitly disallowing the deserialization of executable code or system commands.

The concept of restricted pickling is not a built-in feature of Python's standard `pickle` module but rather a design pattern or a security strategy implemented by developers to mitigate known risks associated with deserializing untrusted data. Proper implementation requires careful consideration of all potential attack vectors and a robust approach to defining what data is considered safe for deserialization.