Default Azure Storage Account Network Access Is Too Permissive

Query id: a5613650-32ec-4975-a305-31af783153ea
Query name: Default Azure Storage Account Network Access Is Too Permissive
Platform: Terraform
Severity: Medium
Category: Insecure Defaults
CWE: 285
URL: Github

Description¶

Default Azure Storage Account network access should be set to Deny
Documentation

Code samples¶

Code samples with security vulnerabilities¶

Positive test num. 1 - tf file

resource "azurerm_resource_group" "example" {
  name     = "positive1-resources"
  location = "West Europe"
}

resource "azurerm_virtual_network" "positive1" {
  name                = "virtnetname"
  address_space       = ["10.0.0.0/16"]
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
}

resource "azurerm_subnet" "positive1" {
  name                 = "subnetname"
  resource_group_name  = azurerm_resource_group.example.name
  virtual_network_name = azurerm_virtual_network.positive1.name
  address_prefixes     = ["10.0.2.0/24"]
  service_endpoints    = ["Microsoft.Sql", "Microsoft.Storage"]
}

resource "azurerm_storage_account" "positive1" {
  name                = "positive1storageaccount"
  resource_group_name = azurerm_resource_group.example.name

  location                 = azurerm_resource_group.example.location
  account_tier             = "Standard"
  account_replication_type = "LRS"

  network_rules {
    default_action             = "Allow"
    ip_rules                   = ["100.0.0.1"]
    virtual_network_subnet_ids = [azurerm_subnet.positive1.id]
  }

  tags = {
    environment = "staging"
  }
}

Positive test num. 2 - tf file

resource "azurerm_resource_group" "example" {
  name     = "positive2-resources"
  location = "West Europe"
}

resource "azurerm_virtual_network" "positive2" {
  name                = "positive2-vnet"
  address_space       = ["10.0.0.0/16"]
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
}

resource "azurerm_subnet" "positive2" {
  name                 = "positive2-subnet"
  resource_group_name  = azurerm_resource_group.example.name
  virtual_network_name = azurerm_virtual_network.positive2.name
  address_prefixes     = ["10.0.2.0/24"]
  service_endpoints    = ["Microsoft.Storage"]
}

resource "azurerm_storage_account" "positive2" {
  name                     = "positive2storageaccount"
  resource_group_name      = azurerm_resource_group.example.name
  location                 = azurerm_resource_group.example.location
  account_tier             = "Standard"
  account_replication_type = "GRS"

  tags = {
    environment = "staging"
  }
}

resource "azurerm_storage_account_network_rules" "positive2" {
  resource_group_name  = azurerm_resource_group.example.name
  storage_account_name = azurerm_storage_account.positive2.name
  storage_account_id = azurerm_storage_account.positive2.id

  default_action             = "Allow"
  ip_rules                   = ["127.0.0.1"]
  virtual_network_subnet_ids = [azurerm_subnet.positive2.id]
  bypass                     = ["Metrics"]
}

Positive test num. 3 - tf file

resource "azurerm_resource_group" "example" {
  name     = "example-resources"
  location = "West Europe"
}

resource "azurerm_storage_account" "positive3" {
  name                     = "positive3storageaccount"
  resource_group_name      = azurerm_resource_group.example.name
  location                 = azurerm_resource_group.example.location
  account_tier             = "Standard"
  account_replication_type = "GRS"
  public_network_access_enabled = true

  tags = {
    environment = "staging"
  }
}

Positive test num. 4 - tf file

resource "azurerm_resource_group" "example" {
  name     = "example-resources"
  location = "West Europe"
}

resource "azurerm_storage_account" "positive4" {
  name                     = "positive4storageaccount"
  resource_group_name      = azurerm_resource_group.example.name
  location                 = azurerm_resource_group.example.location
  account_tier             = "Standard"
  account_replication_type = "GRS"

  tags = {
    environment = "staging"
  }
}

Code samples without security vulnerabilities¶

Negative test num. 1 - tf file

resource "azurerm_resource_group" "example" {
  name     = "example-resources"
  location = "West Europe"
}

resource "azurerm_virtual_network" "negative1" {
  name                = "virtnetname"
  address_space       = ["10.0.0.0/16"]
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
}

resource "azurerm_subnet" "negative1" {
  name                 = "subnetname"
  resource_group_name  = azurerm_resource_group.example.name
  virtual_network_name = azurerm_virtual_network.negative1.name
  address_prefixes     = ["10.0.2.0/24"]
  service_endpoints    = ["Microsoft.Sql", "Microsoft.Storage"]
}

resource "azurerm_storage_account" "negative1" {
  name                = "storageaccountname"
  resource_group_name = azurerm_resource_group.example.name

  location                 = azurerm_resource_group.example.location
  account_tier             = "Standard"
  account_replication_type = "LRS"

  network_rules {
    default_action             = "Deny"
    ip_rules                   = ["100.0.0.1"]
    virtual_network_subnet_ids = [azurerm_subnet.negative1.id]
  }

  tags = {
    environment = "staging"
  }
}

Negative test num. 2 - tf file

resource "azurerm_resource_group" "example" {
  name     = "negative2-resources"
  location = "West Europe"
}

resource "azurerm_virtual_network" "negative2" {
  name                = "negative2-vnet"
  address_space       = ["10.0.0.0/16"]
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
}

resource "azurerm_subnet" "negative2" {
  name                 = "negative2-subnet"
  resource_group_name  = azurerm_resource_group.example.name
  virtual_network_name = azurerm_virtual_network.negative2.name
  address_prefixes     = ["10.0.2.0/24"]
  service_endpoints    = ["Microsoft.Storage"]
}

resource "azurerm_storage_account" "negative2" {
  name                     = "storageaccountname"
  resource_group_name      = azurerm_resource_group.example.name
  location                 = azurerm_resource_group.example.location
  account_tier             = "Standard"
  account_replication_type = "GRS"

  tags = {
    environment = "staging"
  }
}

resource "azurerm_storage_account_network_rules" "negative2" {
  resource_group_name  = azurerm_resource_group.example.name
  storage_account_name = azurerm_storage_account.negative2.name
  storage_account_id = azurerm_storage_account.negative2.id

  default_action             = "Deny"
  ip_rules                   = ["127.0.0.1"]
  virtual_network_subnet_ids = [azurerm_subnet.negative2.id]
  bypass                     = ["Metrics"]
}

resource "azurerm_storage_account_network_rules" "negative2b" {
  resource_group_name  = azurerm_resource_group.example.name
  storage_account_name = azurerm_storage_account.negative3.name
  storage_account_id = azurerm_storage_account.negative3.id

  default_action             = "Deny"
  ip_rules                   = ["127.0.0.1"]
  virtual_network_subnet_ids = [azurerm_subnet.negative2.id]
  bypass                     = ["Metrics"]
}