AKS Network Policy Misconfigured

• Query id: f5342045-b935-402d-adf1-8dbbd09c0eef
• Query name: AKS Network Policy Misconfigured
• Platform: Terraform
• Severity: Medium
• Category: Insecure Configurations
• URL: Github

Description

Azure Kubernetes Service should have the proper network policy configuration to ensure the principle of least privileges, which means that 'network_profile.network_policy' should be defined
Documentation

Code samples

Code samples with security vulnerabilities

Postitive test num. 1 - tf file

resource "azurerm_kubernetes_cluster" "positive1" {
  name                = "example-aks1"
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  dns_prefix          = "exampleaks1"

  default_node_pool {
    name       = "default"
    node_count = 1
    vm_size    = "Standard_D2_v2"
  }

  identity {
    type = "SystemAssigned"
  }

  tags = {
    Environment = "Production"
  }

  network_profile {
    #...other configurations
  }
}

resource "azurerm_kubernetes_cluster" "positive2" {
  name                = "example-aks2"
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  dns_prefix          = "exampleaks2"

  default_node_pool {
    name       = "default"
    node_count = 1
    vm_size    = "Standard_D2_v2"
  }

  identity {
    type = "SystemAssigned"
  }

  tags = {
    Environment = "Production"
  }

}

resource "azurerm_kubernetes_cluster" "positive3" {
  name                = "example-aks1"
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  dns_prefix          = "exampleaks1"

  default_node_pool {
    name       = "default"
    node_count = 1
    vm_size    = "Standard_D2_v2"
  }

  identity {
    type = "SystemAssigned"
  }

  tags = {
    Environment = "Production"
  }

  network_profile {
    network_policy = "roxanne"
  }
}

Code samples without security vulnerabilities

Negative test num. 1 - tf file

resource "azurerm_kubernetes_cluster" "negative1" {
  name                = "example-aks1"
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  dns_prefix          = "exampleaks1"

  default_node_pool {
    name       = "default"
    node_count = 1
    vm_size    = "Standard_D2_v2"
  }

  identity {
    type = "SystemAssigned"
  }

  tags = {
    Environment = "Production"
  }

  network_profile {
    network_policy = "azure"
  }
}

resource "azurerm_kubernetes_cluster" "negative2" {
  name                = "example-aks2"
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  dns_prefix          = "exampleaks2"

  default_node_pool {
    name       = "default"
    node_count = 1
    vm_size    = "Standard_D2_v2"
  }

  identity {
    type = "SystemAssigned"
  }

  tags = {
    Environment = "Production"
  }

  network_profile {
    network_policy = "calico"
  }
}