The vulnerability stems from how JMXServerUtils programmatically configured the JMX/RMI server in vulnerable versions. The commit diff shows the patched version removed dependencies on JVM internals and changed how the RMI registry is bound. The original implementation: 1) Used a custom Registry class that bypassed security constraints, 2) Did not properly enforce authentication requirements when binding the 'jmxrmi' endpoint, 3) Relied on internal sun.rmi classes that weakened security controls. The createJMXServer function was directly responsible for setting up the insecure binding configuration, making it the root cause of the authentication bypass.