Kubelet Not Managing Ip Tables

  • Query id: 5f89001f-6dd9-49ff-9b15-d8cd71b617f4
  • Query name: Kubelet Not Managing Ip Tables
  • Platform: Kubernetes
  • Severity: Medium
  • Category: Networking and Firewall
  • URL: Github

Description

Kubelet argument --make-iptables-util-chains should be true
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - yaml file
apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: foo/bar
      command: ["kubelet"]
      args: ["--make-iptables-util-chains=false"]
  restartPolicy: OnFailure
Positive test num. 2 - yaml file
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
address: "192.168.0.8"
port: 20250
serializeImagePulls: false
evictionHard:
    memory.available:  "200Mi"
makeIPTablesUtilChains: false
Positive test num. 3 - json file
{
    "apiVersion": "kubelet.config.k8s.io/v1beta1",
    "evictionHard": {
        "memory.available": "200Mi"
    },
    "kind": "KubeletConfiguration",
    "makeIPTablesUtilChains": false,
    "port": 20250,
    "serializeImagePulls": false,
    "address": "192.168.0.8"
}

Code samples without security vulnerabilities

Negative test num. 1 - yaml file
apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: foo/bar
      command: ["kubelet"]
      args: ["--make-iptables-util-chains=true"]
  restartPolicy: OnFailure
Negative test num. 2 - yaml file
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
address: "192.168.0.8"
port: 20250
serializeImagePulls: false
evictionHard:
    memory.available:  "200Mi"
makeIPTablesUtilChains: true
Negative test num. 3 - yaml file
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
address: "192.168.0.8"
port: 20250
serializeImagePulls: false
evictionHard:
    memory.available:  "200Mi"

Negative test num. 4 - yaml file 
apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: foo/bar
      command: ["kubelet"]
      args: [""]
  restartPolicy: OnFailure
Negative test num. 5 - json file 
{
    "port": 20250,
    "evictionHard": {
        "memory.available": "200Mi"
    },
    "kind": "KubeletConfiguration",
    "makeIPTablesUtilChains": true,
    "serializeImagePulls": false,
    "address": "192.168.0.8",
    "apiVersion": "kubelet.config.k8s.io/v1beta1"
}