Deny-Storage-CorsRules.json

{
    "name": "Deny-Storage-CorsRules",
    "type": "Microsoft.Authorization/policyDefinitions",
    "apiVersion": "2021-06-01",
    "scope": null,
    "properties": {
        "policyType": "Custom",
        "mode": "All",
        "displayName": "Storage Accounts should restrict CORS rules",
        "description": "Deny CORS rules for storage account for increased data exfiltration protection and endpoint protection.",
        "metadata": {
            "version": "1.0.0",
            "category": "Storage",
            "source": "https://github.com/Azure/Enterprise-Scale/",
            "alzCloudEnvironments": [
                "AzureCloud",
                "AzureChinaCloud",
                "AzureUSGovernment"
            ]
        },
        "parameters": {
            "effect": {
                "type": "String",
                "allowedValues": [
                    "Audit",
                    "Deny",
                    "Disabled"
                ],
                "defaultValue": "Deny",
                "metadata": {
                    "displayName": "Effect",
                    "description": "Enable or disable the execution of the policy"
                }
            }
        },
        "policyRule": {
            "if": {
                "anyOf": [
                    {
                        "allOf": [
                            {
                                "field": "type",
                                "equals": "Microsoft.Storage/storageAccounts/blobServices"
                            },
                            {
                                "count": {
                                    "field": "Microsoft.Storage/storageAccounts/blobServices/cors.corsRules[*]"
                                },
                                "greater": 0
                            }
                        ]
                    },
                    {
                        "allOf": [
                            {
                                "field": "type",
                                "equals": "Microsoft.Storage/storageAccounts/fileServices"
                            },
                            {
                                "count": {
                                    "field": "Microsoft.Storage/storageAccounts/fileServices/cors.corsRules[*]"
                                },
                                "greater": 0
                            }
                        ]
                    },
                    {
                        "allOf": [
                            {
                                "field": "type",
                                "equals": "Microsoft.Storage/storageAccounts/tableServices"
                            },
                            {
                                "count": {
                                    "field": "Microsoft.Storage/storageAccounts/tableServices/cors.corsRules[*]"
                                },
                                "greater": 0
                            }
                        ]
                    },
                    {
                        "allOf": [
                            {
                                "field": "type",
                                "equals": "Microsoft.Storage/storageAccounts/queueServices"
                            },
                            {
                                "count": {
                                    "field": "Microsoft.Storage/storageAccounts/queueServices/cors.corsRules[*]"
                                },
                                "greater": 0
                            }
                        ]
                    }
                ]
            },
            "then": {
                "effect": "[[parameters('effect')]"
            }
        }
    }
}