Skill v1.0.1
currentAutomated scan100/100+3 new
name: detecting-misconfigured-azure-storage description: 'Detecting misconfigured Azure Storage accounts including publicly accessible blob containers, missing encryption settings, overly permissive SAS tokens, disabled logging, and network access violations using Azure CLI, PowerShell, and Microsoft Defender for Storage.
' domain: cybersecurity subdomain: cloud-security tags:
- cloud-security
- azure
- storage-security
- blob-storage
- sas-tokens
- data-protection
version: '1.0' author: mahipal license: Apache-2.0 nist_ai_rmf:
- MEASURE-2.7
- MAP-5.1
- MANAGE-2.4
atlas_techniques:
- AML.T0070
- AML.T0066
- AML.T0082
nist_csf:
- PR.IR-01
- ID.AM-08
- GV.SC-06
- DE.CM-01
mitre_attack:
- T1078.004
- T1530
- T1537
- T1580
- T1610
Detecting Misconfigured Azure Storage
When to Use
- When performing a security audit of Azure Storage accounts across subscriptions
- When responding to Microsoft Defender for Storage alerts about anonymous access or data exfiltration
- When compliance requires verification of encryption, network restrictions, and access logging
- When investigating potential data exposure through publicly accessible blob containers
- When onboarding Azure subscriptions and establishing storage security baselines
Do not use for Azure SQL or Cosmos DB security auditing (use dedicated database security tools), for real-time threat detection on storage operations (use Defender for Storage), or for Azure Files or Data Lake Gen2 specific auditing without adapting the checks.
Prerequisites
- Azure CLI installed and authenticated (
az login) with Reader and Storage Account Contributor roles - Az PowerShell module installed for advanced queries (
Install-Module Az.Storage) - Microsoft Defender for Storage enabled for threat detection
- Access to Azure Resource Graph for cross-subscription queries
- ScoutSuite or Prowler Azure provider for automated assessment
Workflow
Step 1: Enumerate All Storage Accounts and Basic Configuration
List all storage accounts across subscriptions and assess their baseline security settings.
# List all storage accounts across all subscriptionsaz storage account list \--query "[].{Name:name, ResourceGroup:resourceGroup, Location:location, Kind:kind, Sku:sku.name, HttpsOnly:enableHttpsTrafficOnly, MinTLS:minimumTlsVersion, PublicAccess:allowBlobPublicAccess}" \-o table# Use Resource Graph for cross-subscription enumerationaz graph query -q "Resources| where type == 'microsoft.storage/storageaccounts'| project name, resourceGroup, subscriptionId, location,properties.allowBlobPublicAccess,properties.enableHttpsTrafficOnly,properties.minimumTlsVersion,properties.networkAcls.defaultAction" -o table
Step 2: Detect Publicly Accessible Blob Containers
Identify storage accounts and containers allowing anonymous public access to blob data.
# Check each storage account for public blob access settingfor account in $(az storage account list --query "[].name" -o tsv); dopublic=$(az storage account show --name "$account" --query "allowBlobPublicAccess" -o tsv)echo "$account: allowBlobPublicAccess=$public"done# List containers with public access level setfor account in $(az storage account list --query "[?allowBlobPublicAccess==true].name" -o tsv); dokey=$(az storage account keys list --account-name "$account" --query "[0].value" -o tsv)echo "=== $account ==="az storage container list \--account-name "$account" \--account-key "$key" \--query "[?properties.publicAccess!='off' && properties.publicAccess!=null].{Container:name, PublicAccess:properties.publicAccess}" \-o table 2>/dev/nulldone# Test anonymous access to discovered public containerscurl -s "https://ACCOUNT.blob.core.windows.net/CONTAINER?restype=container&comp=list" | head -50
Step 3: Audit Network Access and Firewall Rules
Check for storage accounts accessible from all networks versus those restricted to specific VNets or IP ranges.
# Find storage accounts with default network action set to Allow (open to all networks)az storage account list \--query "[?networkRuleSet.defaultAction=='Allow'].{Name:name, DefaultAction:networkRuleSet.defaultAction, VNetRules:networkRuleSet.virtualNetworkRules}" \-o table# Detailed network rule auditfor account in $(az storage account list --query "[].name" -o tsv); doecho "=== $account ==="az storage account show --name "$account" \--query "{DefaultAction:networkRuleSet.defaultAction, IPRules:networkRuleSet.ipRules[*].ipAddressOrRange, VNetRules:networkRuleSet.virtualNetworkRules[*].virtualNetworkResourceId, Bypass:networkRuleSet.bypass}" \-o jsondone# Find storage accounts with private endpointsaz network private-endpoint list \--query "[?privateLinkServiceConnections[0].groupIds[0]=='blob'].{Name:name, Storage:privateLinkServiceConnections[0].privateLinkServiceId}" \-o table
Step 4: Verify Encryption Settings and Key Management
Ensure all storage accounts use encryption at rest with appropriate key management (Microsoft-managed or customer-managed keys).
# Check encryption configuration for all storage accountsfor account in $(az storage account list --query "[].name" -o tsv); doecho "=== $account ==="az storage account show --name "$account" \--query "{Encryption:encryption.services, KeySource:encryption.keySource, KeyVaultUri:encryption.keyVaultProperties.keyVaultUri, InfraEncryption:encryption.requireInfrastructureEncryption}" \-o jsondone# Find accounts without infrastructure encryption (double encryption)az storage account list \--query "[?encryption.requireInfrastructureEncryption!=true].{Name:name, KeySource:encryption.keySource}" \-o table# Check for accounts using TLS version below 1.2az storage account list \--query "[?minimumTlsVersion!='TLS1_2'].{Name:name, TLS:minimumTlsVersion}" \-o table
Step 5: Audit Shared Access Signatures and Access Keys
Identify overly permissive SAS tokens and check for access key usage patterns.
# Check when storage account keys were last rotatedfor account in $(az storage account list --query "[].name" -o tsv); doecho "=== $account ==="az storage account keys list \--account-name "$account" \--query "[].{KeyName:keyName, CreationTime:creationTime}" \-o tabledone# Check if storage account allows shared key access (should be disabled for AAD-only)az storage account list \--query "[].{Name:name, AllowSharedKeyAccess:allowSharedKeyAccess}" \-o table# Review stored access policies on containers (SAS governance)for account in $(az storage account list --query "[].name" -o tsv); dokey=$(az storage account keys list --account-name "$account" --query "[0].value" -o tsv 2>/dev/null)for container in $(az storage container list --account-name "$account" --account-key "$key" --query "[].name" -o tsv 2>/dev/null); dopolicies=$(az storage container policy list --container-name "$container" --account-name "$account" --account-key "$key" 2>/dev/null)[ -n "$policies" ] && echo "$account/$container: $policies"donedone
Step 6: Check Diagnostic Logging and Monitoring
Verify that storage analytics logging and Azure Monitor diagnostic settings are enabled.
# Check diagnostic settings for storage accountsfor account in $(az storage account list --query "[].name" -o tsv); dorg=$(az storage account show --name "$account" --query "resourceGroup" -o tsv)echo "=== $account ==="az monitor diagnostic-settings list \--resource "/subscriptions/$(az account show --query id -o tsv)/resourceGroups/$rg/providers/Microsoft.Storage/storageAccounts/$account" \--query "[].{Name:name, Logs:logs[*].category, Metrics:metrics[*].category}" \-o json 2>/dev/null || echo " No diagnostic settings configured"done# Check blob service logging propertiesfor account in $(az storage account list --query "[].name" -o tsv); dokey=$(az storage account keys list --account-name "$account" --query "[0].value" -o tsv 2>/dev/null)az storage logging show \--account-name "$account" \--account-key "$key" \--services b 2>/dev/nulldone
Key Concepts
| Term | Definition | |
|---|---|---|
| Blob Public Access | Storage account setting that allows anonymous read access to blob containers and their contents without authentication | |
| Shared Access Signature | Time-limited URI with embedded authentication tokens granting delegated access to Azure Storage resources with specific permissions | |
| Network ACL Default Action | Storage firewall setting that determines whether traffic is allowed or denied by default, with exceptions for specified IPs and VNets | |
| Customer-Managed Key | Encryption key stored in Azure Key Vault that the customer controls for storage encryption instead of Microsoft-managed keys | |
| Stored Access Policy | Named policy on a container that defines SAS permissions, start/expiry times, and can be revoked independently of individual SAS tokens | |
| Defender for Storage | Microsoft Defender plan providing threat detection for anomalous storage access patterns, malware uploads, and data exfiltration |
Tools & Systems
- Azure CLI: Primary tool for querying storage account configuration, containers, and access policies
- Azure Resource Graph: Cross-subscription query engine for efficient enumeration of storage security settings at scale
- Microsoft Defender for Storage: Threat detection service identifying anomalous access patterns and potential data exfiltration
- Prowler Azure: Open-source tool with automated storage security checks aligned to CIS Azure Foundations
- ScoutSuite: Multi-cloud auditing tool with Azure storage-specific checks for public access, encryption, and networking
Common Scenarios
Scenario: Detecting a Storage Account Exposed by a Developer Misconfiguration
Context: A developer creates a storage account for a web application and enables blob public access to serve static files. They accidentally store API keys and database connection strings in a publicly accessible container.
Approach:
- Run
az storage account listfiltering forallowBlobPublicAccess=true - Enumerate containers with public access level set to
bloborcontainer - List contents of public containers to identify sensitive files
- Check Defender for Storage alerts for anomalous access from unexpected IPs
- Immediately set
allowBlobPublicAccesstofalseon the storage account - Rotate any exposed credentials found in public containers
- Enable network ACLs restricting access to the application VNet
- Configure Azure CDN or Front Door for legitimate public content delivery
Pitfalls: Disabling blob public access immediately breaks applications serving content publicly. Coordinate with the development team and implement Azure CDN before disabling public access. SAS tokens generated before a key rotation remain valid until expiry unless the underlying storage key is regenerated.
Output Format
Azure Storage Security Audit Report======================================Subscription: Production (SUB-ID)Assessment Date: 2026-02-23Storage Accounts Audited: 24CRITICAL FINDINGS:[STOR-001] Public Blob Access EnabledAccount: webapp-static-prodContainer: uploads (PublicAccess: blob)Risk: Anonymous users can read all blobs in the containerContents: 1,247 files including .env and config.jsonRemediation: Disable allowBlobPublicAccess, use Azure CDN with SAS[STOR-002] Storage Account Open to All NetworksAccount: data-lake-analyticsDefault Action: Allow (no network restrictions)Risk: Accessible from any network including the internetRemediation: Set default action to Deny, add VNet rulesSUMMARY:Public blob access enabled: 3 / 24Open to all networks: 8 / 24Missing infrastructure encryption: 12 / 24TLS version below 1.2: 2 / 24No diagnostic logging: 10 / 24Shared key access enabled: 18 / 24Keys not rotated in 90+ days: 14 / 24