Azure

How to harden security of Azure Identity (Entra ID)

Entra ID Is the Foundation of Your Security Posture

Azure Identity (Microsoft Entra ID) is the identity provider for every Azure resource, Microsoft 365 service, and thousands of SaaS applications. A compromised identity can access every system that trusts Entra ID. Hardening your identity platform means enforcing strong authentication, implementing least-privilege access, detecting risky behavior, and continuously reviewing access.

Threat Landscape and Attack Surface

Hardening Azure Identity (Entra ID) requires understanding the threat landscape specific to this service. Azure services are attractive targets because they often store, process, or transmit sensitive data and provide control-plane access to cloud infrastructure. Attackers probe for misconfigured services using automated scanners that continuously sweep Azure IP ranges for exposed endpoints, weak authentication, and default configurations.

The attack surface for Azure Identity (Entra ID) includes several dimensions. The network perimeter determines who can reach the service endpoints. The identity and access layer controls what authenticated principals can do. The data plane governs how data is protected at rest and in transit. The management plane controls who can modify the service configuration itself. A comprehensive hardening strategy addresses all four dimensions because a weakness in any single layer can be exploited to bypass the controls in other layers.

Microsoft’s shared responsibility model means that while Azure secures the physical infrastructure, network fabric, and hypervisor, you are responsible for configuring the service securely. Default configurations prioritize ease of setup over security. Every Azure service ships with settings that must be tightened for production use, and this guide walks through the critical configurations that should be changed from their defaults.

The MITRE ATT&CK framework for cloud environments provides a structured taxonomy of attack techniques that adversaries use against Azure services. Common techniques relevant to Azure Identity (Entra ID) include initial access through exposed credentials or misconfigured endpoints, lateral movement through overly permissive RBAC assignments, and data exfiltration through unmonitored data plane operations. Each hardening control in this guide maps to one or more of these attack techniques.

Compliance and Regulatory Context

Security hardening is not just a technical exercise. It is a compliance requirement for virtually every regulatory framework that applies to cloud workloads. SOC 2 Type II requires evidence of security controls for cloud services. PCI DSS mandates network segmentation and encryption for payment data. HIPAA requires access controls and audit logging for health information. ISO 27001 demands a systematic approach to information security management. FedRAMP requires specific configurations for government workloads.

Azure Policy and Microsoft Defender for Cloud provide built-in compliance assessments against these frameworks. After applying the hardening configurations in this guide, run a compliance scan to verify your security posture against your applicable regulatory standards. Address any remaining findings to achieve and maintain compliance. Export compliance reports on a scheduled basis to satisfy audit requirements and demonstrate continuous adherence.

The Microsoft cloud security benchmark provides a comprehensive set of security controls mapped to common regulatory frameworks. Use this benchmark as a checklist to verify that your hardening effort covers all required areas. Each control includes Azure-specific implementation guidance and links to the relevant Azure service documentation.

Step 1: Enable Security Defaults or Conditional Access

# Option A: Enable Security Defaults (free tier baseline)
az rest --method patch \
  --url "https://graph.microsoft.com/v1.0/policies/identitySecurityDefaultsEnforcementPolicy" \
  --body '{"isEnabled": true}'

# Option B: Disable Security Defaults and use Conditional Access (P1 license)
az rest --method patch \
  --url "https://graph.microsoft.com/v1.0/policies/identitySecurityDefaultsEnforcementPolicy" \
  --body '{"isEnabled": false}'

Security Defaults enforce MFA for all users, block legacy authentication, and require MFA for administrative actions. For enterprise environments, use Conditional Access policies for granular control.

Step 2: Create Core Conditional Access Policies

// Policy 1: Require MFA for all administrators
{
  "displayName": "Require MFA for admins",
  "state": "enabled",
  "conditions": {
    "users": { "includeRoles": ["62e90394-69f5-4237-9190-012177145e10"] },
    "applications": { "includeApplications": ["All"] }
  },
  "grantControls": {
    "operator": "OR",
    "builtInControls": ["mfa"]
  }
}

// Policy 2: Block legacy authentication
{
  "displayName": "Block legacy auth",
  "state": "enabled",
  "conditions": {
    "users": { "includeUsers": ["All"] },
    "applications": { "includeApplications": ["All"] },
    "clientAppTypes": ["exchangeActiveSync", "other"]
  },
  "grantControls": {
    "operator": "OR",
    "builtInControls": ["block"]
  }
}

// Policy 3: Require compliant device for sensitive apps
{
  "displayName": "Require compliant device",
  "state": "enabled",
  "conditions": {
    "users": { "includeUsers": ["All"] },
    "applications": { "includeApplications": ["sensitive-app-id"] }
  },
  "grantControls": {
    "operator": "OR",
    "builtInControls": ["compliantDevice"]
  }
}

Step 3: Enable Privileged Identity Management (PIM)

PIM provides just-in-time, time-bound, and approval-based access to privileged roles. No one should have permanent Global Administrator access.

  • Navigate to Entra Admin Center > Identity Governance > PIM
  • Convert all permanent admin assignments to Eligible
  • Configure per-role settings:
    • Max activation duration: 8 hours
    • Require MFA on activation
    • Require approval for Global Admin, Security Admin
    • Require justification for all activations
# List current role assignments (identify permanent admins)
az rest --method get \
  --url "https://graph.microsoft.com/v1.0/roleManagement/directory/roleAssignments?\$filter=roleDefinitionId eq '62e90394-69f5-4237-9190-012177145e10'" \
  --query "value[].{Principal:principalId, Type:directoryScopeId}"

Step 4: Configure Access Reviews

Access reviews ensure that permissions remain appropriate over time. Configure quarterly reviews for:

  • All privileged role assignments (Global Admin, Security Admin, etc.)
  • Guest user access to applications and groups
  • Application permissions and service principal access
# Create access review for Global Admins
az rest --method post \
  --url "https://graph.microsoft.com/v1.0/identityGovernance/accessReviews/definitions" \
  --body '{
    "displayName": "Global Admin Quarterly Review",
    "scope": {
      "query": "/roleManagement/directory/roleAssignments?$filter=roleDefinitionId eq '\''62e90394-69f5-4237-9190-012177145e10'\''",
      "queryType": "MicrosoftGraph"
    },
    "reviewers": [{"query": "/users/security-lead-id", "queryType": "MicrosoftGraph"}],
    "settings": {
      "mailNotificationsEnabled": true,
      "reminderNotificationsEnabled": true,
      "recurrence": {"pattern": {"type": "absoluteMonthly", "interval": 3}}
    }
  }'

Step 5: Enable Identity Protection

Identity Protection uses machine learning to detect risky sign-ins and compromised credentials.

  • Sign-in risk policy: For Medium+ risk, require MFA; for High risk, block access
  • User risk policy: For High risk, require password change

Configure via Entra Admin Center > Protection > Identity Protection > Policies.

Identity and Access Management Deep Dive

Identity is the primary security perimeter in cloud environments. For Azure Identity (Entra ID), implement a robust identity and access management strategy that follows the principle of least privilege.

Managed Identities: Use system-assigned or user-assigned managed identities for service-to-service authentication. Managed identities eliminate the need for stored credentials (connection strings, API keys, or service principal secrets) that can be leaked, stolen, or forgotten in configuration files. Azure automatically rotates the underlying certificates, removing the operational burden of credential rotation.

Custom RBAC Roles: When built-in roles grant more permissions than required, create custom roles that include only the specific actions needed. For example, if a monitoring service only needs to read metrics and logs from Azure Identity (Entra ID), create a custom role with only the Microsoft.Insights/metrics/read and Microsoft.Insights/logs/read actions rather than assigning the broader Reader or Contributor roles.

Conditional Access: For human administrators accessing Azure Identity (Entra ID) through the portal or CLI, enforce Conditional Access policies that require multi-factor authentication, compliant devices, and approved locations. Set session lifetime limits so that administrative sessions expire after a reasonable period, forcing re-authentication.

Just-In-Time Access: Use Azure AD Privileged Identity Management (PIM) to provide time-limited, approval-required elevation for administrative actions. Instead of permanently assigning Contributor or Owner roles, require administrators to activate their role assignment for a specific duration with a business justification. This reduces the window of exposure if an administrator’s account is compromised.

Service Principal Hygiene: If managed identities cannot be used (for example, for external services or CI/CD pipelines), use certificate-based authentication for service principals rather than client secrets. Certificates are harder to accidentally expose than text secrets, and Azure Key Vault can automate their rotation. Set short expiration periods for any client secrets and monitor for secrets that are approaching expiration.

Step 6: Harden Authentication Methods

# Get current authentication methods policy
az rest --method get \
  --url "https://graph.microsoft.com/v1.0/policies/authenticationMethodsPolicy"

Recommended authentication method hierarchy:

  1. FIDO2 security keys — phishing-resistant, highest security
  2. Windows Hello for Business — passwordless, device-bound
  3. Microsoft Authenticator (passwordless) — number matching enabled
  4. Microsoft Authenticator (push) — number matching enabled
  5. SMS/Voice — disable for privileged accounts (SIM swap attacks)

Step 7: Configure Emergency Access (Break-Glass) Accounts

  • Create 2 cloud-only accounts with Global Admin role
  • Use long, complex passwords stored in physical safes
  • Exclude from all Conditional Access policies
  • Exclude from PIM (permanent assignment)
  • Monitor sign-ins and create alerts for any usage
  • Test quarterly to ensure they work

Step 8: Restrict Application Consent

# Disable user consent for applications
az rest --method patch \
  --url "https://graph.microsoft.com/v1.0/policies/authorizationPolicy" \
  --body '{"defaultUserRolePermissions": {"permissionGrantPoliciesAssigned": []}}'

User consent for applications is a common phishing vector. Configure an admin consent workflow so users can request access but administrators must approve.

Step 9: Monitor and Alert on Identity Threats

# Get recent risky sign-ins
az rest --method get \
  --url "https://graph.microsoft.com/v1.0/identityProtection/riskyUsers?\$filter=riskState eq 'atRisk'" \
  --query "value[].{User:userDisplayName, Risk:riskLevel, Detail:riskDetail}"

Forward Entra ID sign-in and audit logs to Log Analytics:

# Configure diagnostic settings for Entra ID
# Navigate to Entra Admin Center > Monitoring > Diagnostic settings
# Send SignInLogs, AuditLogs, NonInteractiveUserSignInLogs,
# ServicePrincipalSignInLogs, and RiskyUsers to Log Analytics

Step 10: Implement Tenant-Wide Security Policies

  • Restrict external collaboration — limit guest invitations to specific domains
  • Disable self-service group creation for regular users
  • Block LinkedIn account integration if not needed
  • Restrict Azure AD administration portal access
  • Enable cross-tenant access settings for B2B collaboration

Defense in Depth Strategy

No single security control is sufficient. Apply a defense-in-depth strategy that layers multiple controls so that the failure of any single layer does not expose the service to attack. For Azure Identity (Entra ID), this means combining network isolation, identity verification, encryption, monitoring, and incident response capabilities.

At the network layer, restrict access to only the networks that legitimately need to reach the service. Use Private Endpoints to eliminate public internet exposure entirely. Where public access is required, use IP allowlists, service tags, and Web Application Firewall (WAF) rules to limit the attack surface. Configure network security groups (NSGs) with deny-by-default rules and explicit allow rules only for required traffic flows.

At the identity layer, enforce least-privilege access using Azure RBAC with custom roles when built-in roles are too broad. Use Managed Identities for service-to-service authentication to eliminate stored credentials. Enable Conditional Access policies to require multi-factor authentication and compliant devices for administrative access.

At the data layer, enable encryption at rest using customer-managed keys (CMK) in Azure Key Vault when the default Microsoft-managed keys do not meet your compliance requirements. Enforce TLS 1.2 or higher for data in transit. Enable purge protection on any service that supports soft delete to prevent malicious or accidental data destruction.

At the monitoring layer, enable diagnostic logging and route logs to a centralized Log Analytics workspace. Configure Microsoft Sentinel analytics rules to detect suspicious access patterns, privilege escalation attempts, and data exfiltration indicators. Set up automated response playbooks that can isolate compromised resources without human intervention during off-hours.

Continuous Security Assessment

Security hardening is not a one-time activity. Azure services evolve continuously, introducing new features, deprecating old configurations, and changing default behaviors. Schedule quarterly security reviews to reassess your hardening posture against the latest Microsoft security baselines.

Use Microsoft Defender for Cloud’s Secure Score as a quantitative measure of your security posture. Track your score over time and investigate any score decreases, which may indicate configuration drift or new recommendations from updated security baselines. Set a target Secure Score and hold teams accountable for maintaining it.

Subscribe to Azure update announcements and security advisories to stay informed about changes that affect your security controls. When Microsoft introduces a new security feature or changes a default behavior, assess the impact on your environment and update your hardening configuration accordingly. Automate this assessment where possible using Azure Policy to continuously evaluate your resources against your security standards.

Conduct periodic penetration testing against your Azure environment. Azure’s penetration testing rules of engagement allow testing without prior notification to Microsoft for most services. Engage a qualified security testing firm to assess your Azure Identity (Entra ID) deployment using the same techniques that real attackers would employ. The findings from these tests often reveal gaps that automated compliance scans miss.

Hardening Checklist

  1. Security Defaults or Conditional Access policies enabled
  2. Core CA policies: MFA for admins, block legacy auth, compliant devices
  3. PIM for all privileged roles (no permanent admins)
  4. Quarterly access reviews for privileged roles
  5. Identity Protection with sign-in and user risk policies
  6. Phishing-resistant authentication methods (FIDO2, WHfB)
  7. Emergency access accounts configured and monitored
  8. Application consent restricted to admin approval
  9. Sign-in and audit logs forwarded to SIEM
  10. Tenant-wide security policies applied

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