Securing VMs with Workload Identity Federation: A Comprehensive Guide

Workload Identity Federation VM Security Non-Human Identity Machine Identity Azure AD Service Principal Managed Identity
Lalit Choda
Lalit Choda
 
June 24, 2025 10 min read

Introduction to Workload Identities and VMs

Did you know that non-human identities, like those used by virtual machines (VMs), are increasingly targeted in cyberattacks? Securing these workload identities is now a critical priority.

Workload identities are unique identifiers assigned to software workloads, such as applications, services, scripts, or containers. Microsoft defines them as the "identities granted to apps or services that need to access and communicate with other services." These identities enable workloads to authenticate and access resources securely.

  • Authentication: Workload identities allow VMs to authenticate with other services and resources without requiring human intervention.
  • Access Control: They facilitate granular control over which resources a VM can access, adhering to the principle of least privilege.
  • Automation: Workload identities are essential for automating tasks and processes within VMs, enhancing efficiency.
  • Security: By using workload identities, organizations can avoid embedding credentials directly in code or configuration files, reducing the risk of credential leakage.
  • Managed Identities: A special type of service principal that eliminates the need for developers to manage credentials Microsoft Entra Workload ID.

For example, in a healthcare setting, a VM running a patient monitoring application can use a workload identity to securely access a database containing patient records, ensuring that only authorized applications can retrieve sensitive information. Similarly, in retail, a VM handling inventory management can use a workload identity to update stock levels in a database without exposing sensitive credentials.

Securing VMs with workload identities involves several key steps:

  1. Identity Provisioning: Assign a unique workload identity to each VM.
  2. Federation: Establish a trust relationship between the VM's identity provider and the resources it needs to access.
  3. Access Policies: Define granular access policies that specify which resources the VM can access and what actions it can perform.
graph LR A[Virtual Machine] --> B{Workload Identity} B --> C[Authentication Service] C --> D{Access Control} D --> E[Protected Resources]

As solutions rely more on non-human entities, the number of non-human identities is increasing dramatically, making them attractive targets for cyberattacks Microsoft Entra Workload ID.

By implementing robust workload identity management, organizations can significantly enhance the security of their VMs and protect against unauthorized access and data breaches.

In the next section, we'll dive into the concept of **Workload Identity Federationnd how it enables secure access to resources across different environments.

Understanding Workload Identity Federation

Did you know that Workload Identity Federation acts like a universal translator for your VMs, allowing them to securely communicate with resources across different environments? It's all about establishing trust.

In essence, Workload Identity Federation enables VMs to access resources without needing traditional credentials, like usernames and passwords. Instead, it relies on a trust relationship between an identity provider and the resource provider. Here are the key benefits:

  • Simplified Credential Management: Forget about the hassle of managing and rotating credentials. Federation eliminates the need to store sensitive information within your VMs. Resources are accessed based on pre-configured trust relationships.
  • Enhanced Security: By removing static credentials, you significantly reduce the risk of credential leakage and unauthorized access. This approach aligns with the principle of least privilege, granting VMs only the necessary permissions.
  • Cross-Environment Access: Workload Identity Federation shines when your VMs need to access resources in different environments, such as on-premises data centers, other cloud providers, or even third-party services. This is especially useful in hybrid and multi-cloud scenarios.
  • Improved Automation: Automate tasks across different platforms seamlessly. This is because the authentication process is handled behind the scenes, allowing your VMs to focus on their core functions.
  • Centralized Control: Manage access policies and trust relationships from a central location. This simplifies administration and ensures consistent security across your entire infrastructure.

Imagine a financial services company using VMs to process transactions. With Workload Identity Federation, these VMs can securely access databases and APIs hosted on different cloud platforms without embedding credentials in the code. The VMs authenticate using short-lived tokens, ensuring secure and efficient data processing.

sequenceDiagram participant VM participant IdentityProvider participant ResourceProvider
VM->>IdentityProvider: Request Token
IdentityProvider->>VM: Issue Token
VM->>ResourceProvider: Access Resource with Token
ResourceProvider->>IdentityProvider: Validate Token
IdentityProvider->>ResourceProvider: Token Valid
ResourceProvider->>VM: Grant Access to Resource

While Workload Identity Federation offers significant advantages, it's crucial to implement it correctly. For instance, this GitHub issue highlights that there is a limit of 20 federated identity credentials per Azure AD Application/Managed Identity. Careful planning and configuration are essential to avoid potential limitations and ensure optimal security.

Now that we understand the fundamentals of Workload Identity Federation, let's explore how to implement it effectively for your VMs in the next section.

Implementing Workload Identity Federation for VMs

Ready to put Workload Identity Federation into action? Let's walk through the key steps to implement this security enhancement for your virtual machines.

Implementing Workload Identity Federation involves several crucial steps, each designed to ensure secure and seamless access to resources.

  • Establish Trust: The cornerstone of Workload Identity Federation is establishing a trust relationship between the identity provider (like Microsoft Entra ID) and the resource provider. This involves configuring both sides to recognize and accept the other's identity assertions.
  • Configure Federated Credentials: Set up federated identity credentials within your identity provider, linking your VM's workload identity to the external identity provider. This configuration tells the identity provider how to validate the tokens presented by your VMs.
  • Assign Permissions: Define granular access policies that specify which resources the VM can access. It's essential to adhere to the principle of least privilege, granting only the necessary permissions to minimize the attack surface.

Remember, there's a limit of 20 federated identity credentials per Azure AD Application/Managed Identity, as highlighted in this GitHub issue. Planning your implementation carefully is crucial to avoid hitting this limit.

Consider a supply chain management system where VMs need to access inventory databases, shipping APIs, and payment gateways. By implementing Workload Identity Federation, each VM can be granted access only to the specific resources it needs, reducing the risk of unauthorized access and data breaches across the entire supply chain.

sequenceDiagram participant VM participant AzureAD participant Resource VM->>AzureAD: Request Access Token AzureAD->>VM: Issue JWT Token VM->>Resource: Present JWT Token Resource->>AzureAD: Validate Token AzureAD->>Resource: Token Valid Resource->>VM: Access Granted

By following these steps, you can effectively implement Workload Identity Federation for your VMs, bolstering your security posture and simplifying credential management.

Now, let's delve into practical examples using Azure and Microsoft Entra ID to illustrate how to configure and manage Workload Identity Federation in a cloud environment.

Practical Examples with Azure and Microsoft Entra ID

Want to see Workload Identity Federation in action? Let's explore how it works with Azure and Microsoft Entra ID, providing a tangible understanding of its configuration and management.

To get started, you'll need an Azure subscription and a Microsoft Entra ID tenant. Here’s what you'll generally do:

  • Create a Managed Identity: Assign a managed identity to your VM. This identity acts as the "who" in the authentication process, representing the workload that needs access.
  • Register an Application in Microsoft Entra ID: This application will represent the external identity provider.
  • Configure Federated Credentials: Establish a trust relationship. Configure the federated identity credentials within your Microsoft Entra ID application, linking your VM's managed identity to the external identity provider.
  • Grant Permissions: Define the necessary permissions for the managed identity to access Azure resources. This is where you specify "what" resources the VM can access.
sequenceDiagram participant VM participant AzureAD participant AzureResource
VM->>AzureAD: Request Access Token
AzureAD->>VM: Issue JWT Token
VM->>AzureResource: Present JWT Token
AzureResource->>AzureAD: Validate Token
AzureAD->>AzureResource: Token Valid
AzureResource->>VM: Access Granted

Imagine a scenario where you have a VM running a data processing application that needs to access Azure Blob Storage. With Workload Identity Federation, the VM can authenticate to Blob Storage using its managed identity, without requiring any hardcoded credentials.

Or consider a financial services application running on a VM that needs to access Azure Key Vault to retrieve encryption keys. By configuring Workload Identity Federation, the VM can securely access Key Vault using its managed identity, ensuring that sensitive keys are protected.

It's crucial to remember the limitation mentioned earlier from this GitHub issue: there is a limit of 20 federated identity credentials per Azure AD Application/Managed Identity. Keep this limit in mind when designing your implementation to avoid potential issues.

Now that we’ve covered practical examples, let's look at key security considerations and best practices to keep in mind.

Security Considerations and Best Practices

Securing your VMs with Workload Identity Federation isn't just about convenience; it's about building a robust defense against potential threats. Understanding the security implications and adopting best practices are crucial for a successful implementation.

  • The principle of least privilege is paramount. Grant VMs only the minimal permissions they need to perform their tasks. For example, a VM processing insurance claims should only have access to the relevant databases and APIs, not the entire system.

  • Regularly review and refine access policies. As business needs evolve, ensure that workload identities still adhere to the principle of least privilege.

  • Implementing workload identities helps organizations avoid embedding credentials directly in code or configuration files, reducing the risk of credential leakage, as defined by Microsoft.

  • Implement comprehensive monitoring and auditing mechanisms. Track all access requests made by workload identities and promptly investigate any anomalies.

  • Regularly review audit logs to identify potential security breaches or misconfigurations.

  • For instance, in a manufacturing environment, monitor VMs accessing IoT sensor data to detect unauthorized attempts to modify production parameters.

  • Protect the keys and certificates used to establish trust between identity providers and resource providers. Store them securely and rotate them regularly.

sequenceDiagram participant VM participant IdentityProvider participant ResourceProvider VM->>IdentityProvider: Request Token IdentityProvider->>VM: Issue Token VM->>ResourceProvider: Access Resource with Token ResourceProvider->>IdentityProvider: Validate Token IdentityProvider->>ResourceProvider: Token Valid ResourceProvider->>VM: Grant Access to Resource Note over ResourceProvider: Regular Security Audits
  • Be aware of the limitations of Workload Identity Federation. For example, remember that there's a limit of 20 federated identity credentials per Azure AD Application/Managed Identity, as noted earlier from this GitHub issue.
  • Plan your implementation carefully to avoid hitting these limits and ensure optimal performance.

By prioritizing these security considerations and best practices, you can confidently leverage Workload Identity Federation to secure your VMs and protect your valuable resources.

Next, we'll compare Workload Identity Federation with other security methods to highlight its unique advantages and disadvantages.

Workload Identity Federation vs. Other Security Methods

Are you relying on outdated security methods for your VMs? Workload Identity Federation offers a modern approach, but how does it stack up against traditional methods?

Let's break down how Workload Identity Federation compares to other common security approaches:

  • Traditional Credentials (usernames/passwords, API keys): These are static and easily compromised. Workload Identity Federation uses short-lived tokens, reducing the attack surface. As Microsoft notes, implementing workload identities helps avoid embedding credentials in code, reducing the risk of leakage.
  • IP Address Restrictions: While helpful, IP restrictions are easily bypassed. Workload Identity Federation focuses on who is accessing the resource, rather than where they are connecting from.
  • Network Segmentation: This limits the blast radius of an attack, but doesn't prevent initial access. Workload Identity Federation adds an extra layer of authentication and authorization, even within a segmented network.
  • Managed Identities: A special type of service principal that eliminates the need for developers to manage credentials Microsoft Entra Workload ID.

Workload Identity Federation offers several key benefits:

  • Simplified Management: No more juggling countless credentials. It streamlines access management by centralizing trust relationships.
  • Enhanced Security: Short-lived tokens and federated trust minimize the risk of credential theft and unauthorized access.
  • Cross-Environment Access: Seamlessly connect VMs to resources across different cloud providers and on-premises environments.

Like any security method, Workload Identity Federation isn't a silver bullet:

  • Complexity: Initial setup can be more complex than simply creating a username and password.
  • Dependency on Identity Provider: Relies on the availability and security of the identity provider.
  • Credential Limits: Keep in mind that there's a limit of 20 federated identity credentials per Azure AD Application/Managed Identity, as noted earlier from this GitHub issue.

Imagine a retail company using VMs to manage inventory across multiple warehouses. With Workload Identity Federation, each VM can securely access inventory databases hosted on different cloud platforms without needing to store credentials locally. The VMs authenticate using short-lived tokens, ensuring secure and efficient inventory management.

Or consider a manufacturing plant where VMs control robotic arms. Workload Identity Federation can ensure that only authorized VMs can access and control these critical systems, preventing unauthorized modifications.

By understanding the strengths and weaknesses of Workload Identity Federation, organizations can make informed decisions about their VM security strategies.

Now, let's peek into the future and explore emerging trends in Workload Identity and Federation.

Lalit Choda
Lalit Choda
 

NHI Evangelist : with 25+ years of experience, Lalit Choda is a pioneering figure in Non-Human Identity (NHI) Risk Management and the Founder & CEO of NHI Mgmt Group. His expertise in identity security, risk mitigation, and strategic consulting has helped global financial institutions to build resilient and scalable systems.

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