The Importance of Threat Modeling for Building Secure Workloads in AWS

In cybersecurity, the only things evolving faster than technology are the threats against it. At this point, your smart fridge could be part of the plan for world domination. As secure design engineers and application development lifecycle (ADLC) personnel, our role in ensuring the safety of our organizations’ digital assets cannot be overstated. One crucial technique that should be a part of every security toolkit is threat modeling, particularly when designing and deploying workloads on Amazon Web Services (AWS). In this article, we will explore the significance of threat modeling in the AWS environment, its benefits, and how to integrate it into your secure development process.

Understanding Threat Modeling

Alright I’ve at least piqued your interest. “What is Threat Modeling,” you say? Glad you asked!

Threat modeling is a structured process for identifying potential security threats and vulnerabilities in a system or application. It helps security professionals, developers, and architects systematically analyze and assess the security risks associated with a particular design or implementation. By proactively identifying potential threats, teams can take steps to mitigate them before they can be exploited.

Let’s take that potentially devious smart fridge as an example. 

1. Asset Identification:
   1. The fridge itself, of course, which is packed with sensors, a Wi-Fi connection, and probably an unsettlingly cheerful touchscreen interface.
   2. The food inventory within - imagine if the fridge knew when you were running low on milk and autonomously placed an order? Convenient or a dairy dictatorship? You decide.
   3. Your personal details, like your shopping habits, preferred grocery store location, or the unhealthy amount of chocolate you hide in the crisper.
      
2. Threat Identification:
   1. A hacker could turn the temperature up, spoiling your food and creating a biological hazard.
   2. The fridge might become a node in a botnet, participating in DDoS attacks.
   3. Ransomware could lock you out, demanding cryptocurrency before you can access your homemade lasagna.
      
3. Vulnerability Analysis:
   1. The fridge’s software could be out-of-date, like that yogurt in the back you forgot about. Old firmware is a hacker’s happy hour.
   2. Weak passwords - “1234” won’t protect your post-midnight snack raids from prying digital eyes. No, “0000” isn’t good enough either.
   3. Overly permissive network access - does your fridge really need to communicate with every device in the house? That’s a cold shoulder waiting to happen.
      
4. Risk Assessment:
   1. The likelihood of someone actually targeting your fridge might be low unless you’re a high-profile individual or your grocery list includes state secrets.
   2. However, the impact could range from mild (unexpected defrosting of frozen goods) to severe (compromised personal payment information from integrated grocery ordering systems).
      
5. Mitigation Strategies:
   1. Regularly update your smart fridge’s software like you would any other device. Remember, even your fridge has patch notes.
   2. Use strong, unique passwords for your fridge’s interface - “IL0veIceCream” is better than “icecream,” but still not ideal.
   3. Secure your home Wi-Fi network, and make sure the fridge isn’t broadcasting on the guest Wi-Fi with no encryption.

Threat modeling serves as the cornerstone of a secure design process. If I had to pick the top four things it enables organizations to do, I’d map them out as follows:

1. Identify Weaknesses Early Early identification of vulnerabilities and weaknesses in your AWS workloads is crucial. Threat modeling allows you to uncover potential security issues at the design stage, significantly reducing the cost and effort required to fix them later in the development process.
   
2. Prioritize Security Investments Not all threats are created equal. Threat modeling helps you prioritize security efforts by focusing on the most critical and likely threats. This ensures resources are allocated efficiently, addressing the most significant risks first.
   
3. Foster a Security Mindset Threat modeling encourages a security-first mindset within your development and operational teams. When security considerations are integrated into the design process, it becomes a natural part of the development lifecycle.
   
4. Ensure Regulatory Compliance Many industries are subject to strict regulatory requirements regarding data protection and security. Threat modeling helps you demonstrate due diligence in identifying and mitigating security risks, which can be crucial for compliance.

Threat Modeling in the AWS Environment

AWS offers a wide range of services and configurations, making it a powerful and flexible platform for building and deploying applications. However, this flexibility also introduces complexity, which can lead to security challenges. Threat modeling in the AWS environment requires specific considerations and methodologies.

First, you’ll want to make sure you understand the AWS shared responsibility model. In this model, AWS is responsible for the security of the cloud infrastructure (such as data centers and physical security), while you are responsible for securing your applications, data, and configurations. When threat modeling in AWS, it’s essential to recognize this division of responsibilities and ensure your models account for both.

Next, you’ll want to ensure you are leveraging secure frameworks and benchmarks. AWS provides the AWS Well-Architected Framework, a set of best practices for building secure, high-performing, resilient, and efficient infrastructure for applications. It includes security pillars, which provide guidance on designing secure workloads. (Ahem, it also specifically calls out the importance of identifying and prioritizing risks using a threat model!) Integrating these best practices into your threat modeling process can significantly enhance the security of your AWS workloads.

The Center for Internet Security (CIS) provides a comprehensive set of guidelines known as CIS Benchmarks for securing various tech stacks and the different cloud service provider environments to the minimum secure standards for the CIS first 20 controls. The AWS version is called the “CIS Benchmark for Foundational Security.” These benchmarks offer detailed step-by-step checks and improvements for configuring AWS services securely. By aligning your AWS workloads with these benchmarks, you can ensure your foundational security measures are in line with industry best practices, reducing the risk of common misconfigurations and vulnerabilities.

In the context of AWS security, the Zero Trust model is a strategic approach that assumes no trust, even within your organization’s network. This approach emphasizes continuous verification of identities and devices, stringent access controls, and real-time monitoring of network traffic. Implementing Zero Trust principles within AWS environments is crucial for mitigating insider threats, unauthorized access, and lateral movement by attackers, ultimately enhancing your security posture.

Lastly, you will want to model for AWS-specific threats and vulnerabilties.This might involve threats related to identity and access management, misconfigurations, data exposure, and more. Understanding the unique risks of AWS services and configurations is vital. The MITRE ATT&CK framework for Cloud is an excellent place to start for potential threats.

Integrating Threat Modeling Into the ADLC

Ok, so you know what threat modeling is and you’re familiar with the AWS-specific considerations and methodologies - now what? To fully realize the benefits of threat modeling, it should be seamlessly integrated into your ADLC. Here’s how to make it an integral part of your secure development process:

1. Start Early
   Begin threat modeling as early as possible in the development process. Ideally, it should be initiated during the design phase, well before any code is written. Because nobody, not even developers, enjoy going back through thousands of lines of their own code. Early threat modeling helps you address security issues when they are most cost and time-effective to fix. Of course, no product is completely perfect when it is deployed. The goal is to anticipate as much as possible to give ourselves the best foot forward. Sometimes, we don’t know how a system got this way, we just inherit it as is. It’s always our goal to make recommendations based on where we are to get where we want to be regardless.
   
2. Take a Collaborative Approach
   Involve cross-functional teams in the threat modeling process. This includes developers, architects, security experts, compliance experts, offensive teams, and other relevant stakeholders. Collaboration ensures different perspectives are considered, leading to more comprehensive threat models.
   
3. Leverage Automation and Tools
   Leverage threat modeling tools such as OWASP Threat Dragon and Lucid Chart to automate and streamline the process. There are various tools available built into AWS as well such as AWS Threat Composer and IriusRisk or ThreatModeler via the AWS Marketplace that can assist in threat identification, risk assessment, and documentation. These tools can help your team work more efficiently and consistently.
   
4. Document Everything
   I’m serious. Include what you ate that morning too. (Ok, maybe that’s a step too far, besides let’s be honest: the smart fridge already knows.) But, threat modeling should result in clear and well-documented findings, threats, and correlating mitigations and after-action items. These might include to confirm a policy or setting, perform a rule check, or add implementation of a control to the roadmap. This documentation serves as a valuable reference for your team and can be essential for compliance and auditing purposes.
   
5. Continuously Improve and Iterate
   As your system evolves and new threats emerge, or as new features are being developed and deployed, revisit and update your threat models. Continuous improvement is essential for maintaining the security of your AWS workloads over time.

Conclusion

Securing workloads in AWS can be especially difficult due to the ease and scalability of the cloud. Threat modeling is a proven proactive technique that helps you identify and mitigate potential security risks early in the development process. By understanding the shared responsibility model, leveraging AWS best practices, and following a structured threat modeling process, you can build more secure and resilient systems on AWS. Remember, security is not a one-time effort but a continuous journey, and threat modeling is a valuable tool to navigate that journey successfully in the AWS environment.

If you’d like to learn more about enhancing your AWS workload security through threat modeling, download our white paper or reach out to our team at threatmodeling@aquia.us.

If you have any questions, or would like to discuss this topic in more detail, feel free to contact us and we would be happy to schedule some time to chat about how Aquia can help you and your organization.