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.

In all Kubernetes versions prior to v1.11.8, v1.12.6, and v1.13.4, users that are authorized to make patch requests to the Kubernetes API Server can send a specially crafted patch of type "json-patch" (e.g. `kubectl patch --type json` or `"Content-Type: application/json-patch+json"`) that consumes excessive resources while processing, causing a Denial of Service on the API Server.

It was found that Kubernetes as used by Openshift Enterprise 3 did not correctly validate X.509 client intermediate certificate host name fields. An attacker could use this flaw to bypass authentication requirements by using a specially crafted X.509 certificate.

Kubernetes in OpenShift3 allows remote authenticated users to use the private images of other users should they know the name of said image.

Openshift allows remote attackers to gain privileges by updating a build configuration that was created with an allowed type to a type that is not allowed.

The API server in Kubernetes does not properly check admission control, which allows remote authenticated users to access additional resources via a crafted patched object.