Insecure Deserialization

Hey there! Let's talk about one of the top 10 OWASP vulnerabilities called Insecure Deserialization. It's a fancy term that refers to a vulnerability where a server tries to unpack data provided by a user, but that data actually contains hidden malicious code. Sneaky, right? This vulnerability can occur in various programming languages like Python, Java, PHP, Ruby, and more.

Before diving deeper in to the vulnerability itself, lets try to grasp what serialization is.

What is Serialization and Deserialization?

Serialization can be defined as the process of converting complex data structures and objects into a stream of bytes. This is necessary because this is a transportable format of the data and can then be stored into a file, database or memory for later use. When an object is serialized, ideally its state is preserved, meaning, the object’s attributes along with their values remains unchanged

Obviously, then deserialization refers to the opposite, that is, the converting a stream of bytes from a file, database or memory into a complex data structure or object which is human readable.

What is Insecure Deserialization?

An insecure deserialization also known as object injection, as previously mentioned, is a vulnerability that occurs when a server tries to unpack the data provided by a user which triggers the execution of malicious code which was hidden into this data. This could leak out sensitive information or even provide with remote code execution which could be devastating for a company.

So if insecure deserialization is so dangerous how can you protect yourself?

Insecure deserialization can indeed be quite dangerous, but there are ways to protect yourself. One important step is to never pass a serialized object manipulated by an untrusted user to the deserialize function. This prevents potential manipulation of the object and direct execution of malicious code. Instead, consider using a secure and lightweight data-interchange format like JSON.

Additionally, If you do have to accept serialized objects, here are some tips to mitigate insecure deserialization:

• Implement digital signatures and other integrity checks to prevent malicious object creation or data interference.
• Run deserialization code in low privilege environments.
• Keep a log of deserialization exceptions and failures.
• Monitor and restrict all incoming and outgoing network activity from deserialization containers and servers.
• Utilize deserialization methods like JSON, XML, and YAML that are language-agnostic.

Alright, folks! That's a wrap on our little chat about Insecure Deserialization. Remember, this vulnerability is like a sneaky ninja hiding malicious code in innocent-looking data.

Check out the above video on Insecure Deserialization by PwnFunction where he digs deeper into how an actual attack is carried out.

Until next time. Happy Hacking!