Brian Vermeer

Java Champion | Developer | Speaker

09 August 2022

Hackers refer to deserialization in Java as “the gift that keeps on giving”. But what is actually the problem? In most cases, it is not even your own code that creates this security vulnerability. This problem is also not restricted to Java’s custom serialization framework. When deserializing JSON, XML, or YAML, similar issues can occur as well.

In this talk, I explain how deserialization vulnerabilities work natively in Java and how attack chains are created. Next, I will show that deserializing XML, JSON, and YAML can also get you into trouble. Many different problems can occur when deserializing data, think about the recently discovered problems with log4j. In this session I will use several demos to illustrate various security issues.

How do you avoid these issues? I will give you some pointers on how to mitigate these problems in your own applications. At the end of this session, you will have an understanding of the problem space and be able to take action in your code to prevent it.

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