ObjectInputStream

This course details the exploitation of a Java serialization vulnerability in a Spring application. When a Java application unserializes arbitrary data using the readObject() method, it opens the door for attackers to trigger unexpected behaviors and gain command execution. Exploiting this vulnerability requires finding a chain of gadgets in the libraries loaded by the application that can be manipulated to achieve code execution.

The tool ysoserial is used to generate malicious Java objects that exploit this vulnerability. By understanding the structure and behavior of serialized Java objects, one can identify and exploit the entry points in the application. This course also emphasizes the importance of avoiding the unserialization of user-controlled data to prevent such vulnerabilities.