CVE-2020-9x9x

The Code Review Patch challenges provide an engaging way to enhance your code review skills by analyzing vulnerable code alongside its patch. Initially, you attempt to find the vulnerability without looking at the patch, fostering a deeper understanding of the code. Should you struggle to identify the issue or wish to confirm your suspicions, the patch is available for comparison.

In the CVE-2020-9x9x challenge, we review a Java class SocketNode13 used for deserializing LoggingEvent objects received over a socket connection. The code reveals a critical flaw where an ObjectInputStream reads data directly from the socket, leading to insecure deserialization and potential remote code execution vulnerabilities. The provided diff shows that the developers chose to mitigate the risk by entirely removing the vulnerable file, effectively eliminating the hazardous functionality.