CNI plugin does not support network policies

Docs > Datadog Security > Code Security > Infrastructure as Code (IaC) Security > IaC Security Rules > CNI plugin does not support network policies

Metadata

Id: kubernetes-cni-plugin-does-not-support-network-policies

Platform: Kubernetes

Severity: Medium

Category: Networking and Firewall

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Provider Reference

Description

Ensure the cluster uses a CNI plugin that supports NetworkPolicies. CNI plugins that do not support NetworkPolicies (for example, Flannel) cannot enforce pod- or namespace-level network restrictions, which may allow unrestricted cluster traffic and increase the attack surface.

Compliant Code Examples

kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-system
  labels:
    tier: node
    app: calico
data:
  cni-conf.json: |
    {
      "name": "cbr0",
      "plugins": [
        {
          "type": "calico",
          "delegate": {
            "hairpinMode": true,
            "isDefaultGateway": true
          }
        },
        {
          "type": "portmap",
          "capabilities": {
            "portMappings": true
          }
        }
      ]
    }
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "vxlan"
      }
    }

Non-Compliant Code Examples

kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-system
  labels:
    tier: node
    app: flannel
data:
  cni-conf.json: |
    {
      "name": "cbr0",
      "plugins": [
        {
          "type": "flannel",
          "delegate": {
            "hairpinMode": true,
            "isDefaultGateway": true
          }
        },
        {
          "type": "portmap",
          "capabilities": {
            "portMappings": true
          }
        }
      ]
    }
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "vxlan"
      }
    }