Description
Cloud Native Computing Foundation (CNCF) CNI (Container Networking Interface) 0.7.4 has a network firewall misconfiguration which affects Kubernetes. The CNI 'portmap' plugin, used to setup HostPorts for CNI, inserts rules at the front of the iptables nat chains; which take precedence over the KUBE- SERVICES chain. Because of this, the HostPort/portmap rule could match incoming traffic even if there were better fitting, more specific service definition rules like NodePorts later in the chain. The issue is fixed in CNI 0.7.5 and Kubernetes 1.11.9, 1.12.7, 1.13.5, and 1.14.0.
