Weak TLS Cipher Suites

• Query id: 510d5810-9a30-443a-817d-5c1fa527b110
• Query name: Weak TLS Cipher Suites
• Platform: Kubernetes
• Severity: Medium
• Category: Encryption
• CWE: 326
• URL: Github

Description

TLS Connection should use strong Cipher Suites
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: ["--tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256"]
  restartPolicy: OnFailure

Positive test num. 2 - yaml file

apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
      command: ["kube-apiserver"]
      args: ["--tls-cipher-suites=TLS_RSA_WITH_RC4_128_SHA"]
  restartPolicy: OnFailure

Positive test num. 3 - yaml file

apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
address: "192.168.0.8"
port: 20250
protectKernelDefaults: false
serializeImagePulls: false
tlsCertFile: "someFile.txt"
tlsPrivateKeyFile: "someFile.txt"
tlsCipherSuites: ["TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256","TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256"]
evictionHard:
    memory.available:  "200Mi"

Positive test num. 4 - json file

{
    "kind": "KubeletConfiguration",
    "apiVersion": "kubelet.config.k8s.io/v1beta1",
    "port": 10250,
    "readOnlyPort": 10255,
    "cgroupDriver": "cgroupfs",
    "hairpinMode": "promiscuous-bridge",
    "serializeImagePulls": false,
    "featureGates": {
      "RotateKubeletClientCertificate": true,
      "RotateKubeletServerCertificate": true
    }
  }

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: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
      command: ["kube-apiserver"]
      args: ["--tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256"]
  restartPolicy: OnFailure

Negative test num. 2 - 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: ["--tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256"]
  restartPolicy: OnFailure

Negative test num. 3 - 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. 4 - json file

{
    "kind": "KubeletConfiguration",
    "apiVersion": "kubelet.config.k8s.io/v1beta1",
    "port": 10250,
    "readOnlyPort": 10255,
    "cgroupDriver": "cgroupfs",
    "hairpinMode": "promiscuous-bridge",
    "serializeImagePulls": false,
    "tlsCipherSuites": ["TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256","TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256"],
    "featureGates": {
      "RotateKubeletClientCertificate": true,
      "RotateKubeletServerCertificate": true
    }
  }