Design/Logic Flaw

The clustered setup of Apache MXNet allows users to specify which IP address and port the scheduler will listen on via the DMLC_PS_ROOT_URI and DMLC_PS_ROOT_PORT env variables. In versions older than 1.0.0, however, the MXNet framework will listen on 0.0.0.0 rather than user specified DMLC_PS_ROOT_URI once a scheduler node is initialized. This exposes the instance running MXNet to any attackers reachable via the interface they didn’t expect to be listening on. For example: If a user wants to run a clustered setup locally, they may specify to run on 127.0.0.1. But since MXNet will listen on 0.0.0.0, it makes the port accessible on all network interfaces.