A vulnerability exists in Keycloaks server distribution where enabling debug mode (–debug ) insecurely defaults to binding the Java Debug Wire Protocol (JDWP) port to all network interfaces (0.0.0.0). This exposes the debug port to the local network, allowing an attacker on the same network segment to attach a remote debugger and achieve remote code execution within the Keycloak Java virtual machine.
The product assigns the address 0.0.0.0 for a database server, a cloud service/instance, or any computing resource that communicates remotely.
When a server binds to the address 0.0.0.0, it allows connections from every IP address on the local machine, effectively exposing the server to every possible network. This might be much broader access than intended by the developer or administrator, who might only be expecting the server to be reachable from a single interface/network.