Course

In this lab, you are presented with a piece of vulnerable code alongside its patch. Your task is to review the code and attempt to identify the security issue without relying on the provided patch. This approach simulates real-world scenarios where developers must pinpoint vulnerabilities without immediate guidance. Once you have given it a thorough look, you can verify your findings by examining the diff file to see the changes made to mitigate the vulnerability.

The provided code is from the `WebdavServlet.java` file, which is a part of the Apache Tomcat project. The patch addresses several security concerns, including setting entity resolvers to prevent XXE (XML External Entity) attacks and improving the handling of WebDAV methods. Understanding these changes will not only help you identify the specific issues but also deepen your knowledge of secure coding practices.