Sep 16, 2024
In the AI age, the importance of effective threat modeling cannot be overstated. As organizations increasingly rely on complex software systems, identifying and mitigating potential security risks early in the development process becomes essential.
This blog delves into the intricacies of threat modeling, exploring its methodologies, such as the STRIDE framework, and how it empowers developers to anticipate and address vulnerabilities. By fostering a proactive security mindset, threat modeling not only enhances application resilience but also safeguards sensitive data against emerging threats.
Approach to Threat Modeling
Threat modeling is a systematic method designed to identify and rank potential threats and vulnerabilities in software. It focuses on understanding possible attackers, their objectives, and the probable techniques they are about to deploy to exploit system vulnerabilities. The aim is to detect security risks in the earlier stages of the software development process and mitigate them promptly before deployment. In short, threat modeling delivers a context for developing a viable cybersecurity strategy after considering all the security gaps.
Identification and Assessment of Risks
The process starts by setting up security requirements and determining assets within the system. It involves outlining the architecture and virtually disintegrating the application to analyze entry and exit points, trust boundaries, data flows, and privileged code.
Proactive Security Measures
Threat modeling is designed to be proactive. By accomplishing threat modeling in the initial stages of app design, it becomes easy to identify high-value assets and possible attack surfaces. Developers become aware of the security implications, which helps them make better coding and configuration decisions.
STRIDE Threat Modeling Framework
While there are many frameworks to perform Threat Modeling, STRIDE, Developed by Microsoft, is the most popular. While STRIDE may not be the perfect framework for you, understanding how STRIDE works can help you design your threat modeling program better
STRIDE categorizes security threats into six distinct classes. Here are the snippets of each category and the suggested mitigation strategies for the same:
Spoofing Identity - These are threats in which an attacker impersonates a user, device, or system component. Common examples include password guessing, masquerading attacks, session hijacking, etc.
Mitigation examples - Implement robust authentication mechanisms, such as multi-factor authentication, to verify user identities and prevent unauthorized access.
Tampering with Data - Tampering threats relate to unauthorized modification, omission, or insertion of data. Examples include unauthorized data access, data integrity attacks, or modifying data in transit.
Mitigation examples: Deployment of data validation and encryption techniques to ensure data integrity, shielding against unauthorized modifications.
Repudiation - Repudiation threats involve scenarios where an actor denies or disputes their actions.
Mitigation examples - Robust logging and audit trails sequences must be there in place to track user actions and provide accountability.
Information Disclosure - This category caters to threats related to exposure to sensitive information or unauthorized access. Common examples include data leakage or information exposure through error messages.
Mitigation examples: Identification of sensitive data paths and implementation of data masking or strict access controls to enforce confidentiality.
Denial of Service (DoS): These treats typically involve attacks that disrupt or damage the availability of a system (or resource).
Mitigation examples: Deployment of mechanisms such as load balancers or firewalls to mitigate DoS attacks and implementing rate limiting and request validation.
Elevation of Privilege: Elevation of privilege occurs when an attacker acquires unauthorized access to sensitive (and restricted) functionalities beyond their clearance level. Common examples include privilege escalation attacks and bypassing access controls.
Mitigation examples - Enforcement of role-based access controls, adhering to the principle of least privilege, security audits, etc.
Limitations of STRIDE
Despite its benefits, STRIDE has certain limitations. Here are some of them.
Benefits of STRIDE at a Glance
Here are the key benefits of STRIDE at a glance.
How does Threat Modeling help Mitigate Risk?
Threat modeling helps to mitigate risks in the following ways:
Early Detection
A high-level threat model is ideally established during the concept or planning phase and continuously refined as the project evolves. As more details emerge, new vulnerabilities and attack vectors are introduced. Therefore, the ongoing threat modeling process must identify, assess, and mitigate these emerging threats.
Focus on High-Risk Areas
By addressing the most significant threats first, organizations can maximize the impact of their security measures and optimize resource allocation.
In this context, the STRIDE framework (mentioned above) can help organizations to prioritize critical vulnerabilities and focus their security efforts on them. This targeted approach ensures that the most critical vulnerabilities are acted upon quickly, enhancing the overall security posture.
Adaptability
As new technologies develop and innovative attack vectors appear, it is essential for threat modeling to adapt continuously to these shifts. This adaptability is vital for ensuring strong security throughout the entire lifecycle of an application or system. Regularly updating threat models aids in reducing potential harm by tackling threats before they can escalate.
For best results, updation of threat models must be done after events such as:
When a new feature arrives
Occurrence of security incidents
Architectural or infrastructure modifications
Creating a Threat Model in a Traditional Setup
Adopting a structured approach to application threat modeling has allowed traditional modeling to identify, quantify, and manage security risks tied to an application. However, modern day threats require a different approach. Integrating threat modeling into your software development process enhances product security. This method views a system from the standpoint of a potential attacker rather than a defender.
For example, Seezo is a great platform that specializes in providing automated security design reviews for software features. It simplifies context-specific security requirements to developers before they begin coding, ensuring that security considerations are integrated into the development process from the outset.
Fig: Security Model of System (Source: Link)
The traditional threat modeling process, on the other hand, consists of four main steps, each typically documented as it is completed. The documentation results in a threat model specific to the application. It is important to differentiate between the process of threat modeling and the creation of the threat model document itself.
Step 1: Defining the Scope
The initial step in threat modeling involves gaining a thorough understanding of the application. This may include:
Creating diagrams, often data flow diagrams (DFDs), to map out the system.
Identifying entry points where a potential attacker could interact with the application.
Determining key "assets" within the application.
Establishing trust levels that indicate the access rights the application grants to external entities.
Reviewing or creating user stories ( may also extend to include abuse stories or misuse cases).
Data flow diagrams are commonly used to depict the system, illustrating the various pathways and highlighting trust or privilege boundaries. This process is sometimes referred to as “decomposing the application”. It is a technique often employed by consultants during threat modeling or architectural reviews. The output typically takes the form of a Threat Model document.
In some cases, the approach "Threat modeling every story" is advocated, which is the responsibility of developers or operations teams. For this approach, the concept of "decomposing the application" may not be relevant.
This step also often highlights “assets”. These can be items to protect, stepping stones, or targets for attackers. These assets can sometimes be out of the project’s scope or difficult to identify before an attacker brings them to attention.
Step 2: Identifying Threats
Identifying threats is crucial, often requiring the use of a threat categorization method. The STRIDE methodology is robustly applied in threat modeling. The purpose of threat categorization is to identify threats from the attacker's perspective (as done with STRIDE). The DFDs created in Step 1 help pinpoint potential threat targets from this perspective, such as data sources, processes, data flows, and user interactions.
These threats can be further organized using threat trees, with a separate tree for each threat objective. Common threat lists, supplemented with examples, can aid in identifying these threats. Use cases and abuse cases can demonstrate how current protective measures might be bypassed or where protection is lacking.
Step 3: Identifying Countermeasures and Mitigation
Mitigating vulnerabilities often involves implementing countermeasures. These can be identified using threat-countermeasure mapping lists. Prioritizing these countermeasures can be complex, with many approaches available. Organizations must choose the methods that best suit their needs. Some common factors in this process include the chances of an attack, potential damage, and the complexity or cost of mitigation.
The risk mitigation strategy may involve evaluating threats based on their business impact. Once the impact is understood, possible responses include:
Acceptance: Determine that the business impact is acceptable and document who has made this decision.
Elimination: Remove components that enable the vulnerability.
Mitigation: Introduce checks or controls to reduce the risk or its impact.
Transfer: Shift the risk to an insurer or another party.
Step 4: Evaluation of Threat Model
Begin by verifying that the work has been completed. This can be done by ensuring that there are records of diagrams, threat lists, and control lists.
Scope the Work
This step is framed to help those outside the application’s development gain a clear understanding of the application and its interactions with external entities. This goal is achieved through information gathering and documentation, using a defined structure to ensure the correct data is collected.
Threat Model Information
Waterfall-style or consultant-produced threat model documents typically include:
Application Name: The name of the application under review.
Application Version: The version of the application being examined.
Description: A high-level overview of the application.
Document Owner: The individual responsible for the threat modeling document.
Participants: The team members involved in the threat modeling process for this application.
Reviewer: The person(s) responsible for reviewing the threat model.
As a security process, people often have several misconceptions about threat modeling. While some people are of the opinion that threat modeling is a design-stage activity, others think penetration testing does the work equally well. Some even think that the process is too complex. Listed below are some common misconceptions:
While automated testing in the software development lifecycle (SDLC) can efficiently identify code vulnerabilities, it fails to fully replace the need for threat modeling. Manual security assessments, such as threat modeling, excel at uncovering design flaws that automated tests may overlook1.
Conducting threat modeling only after deployment is insufficient. Understanding the issues in the current deployment is crucial for informing future security architecture strategies. By monitoring weaknesses, organizations can respond more quickly and effectively to remediate risks. Without a comprehensive understanding of the potential threats facing an application, it is impossible to ensure that all risks are adequately addressed1.
Many developers may initially find the concept of threat modeling intimidating, as it can seem complex at first glance. However, by breaking down the process into manageable steps, performing a threat model on a simple web application or even a complex architecture becomes more systematic. The key is to start with basic best practices and gradually build upon them as familiarity and expertise increase.
Threat Modeling - Common Misconceptions
Threat modeling, as a security process, is often misunderstood. While some assume it is only relevant during the design phase, others view it as an optional task that is replaceable by penetration testing or code reviews. Some even feel that it is overly complex. Here’s why these misunderstandings should be corrected.
Automated testing in the SDLC cannot replace threat modeling. While automated tests effectively identify code vulnerabilities, manual security assessments like threat modeling are crucial for detecting design flaws.
Threat modeling remains indispensable even after deployment. Addressing issues in the current deployment addresses future security strategies, and monitoring for vulnerabilities enables quicker, more effective remediation. It’s impossible to manage all risks without recognizing potential threats.
Threat modeling isn’t as complicated as it seems. Many developers may find it intimidating initially. However, breaking down the process into manageable steps can make it systematic, whether working on a simple web application or a more complex architecture. The key is to begin with fundamental best practices.
How Can Automation and AI Enhance Threat Modeling?
Traditionally, threat modeling was a manual process where security experts and stakeholders would map out systems on whiteboards. However, with the rise of DevSecOps, security teams now face the challenge of keeping pace with rapid development cycles while minimizing security friction. This has led to the integration of automation in threat modeling.
Automated threat modeling should complement the work of security engineers rather than replace it. Human oversight remains crucial because creating a system model that a computer can effectively analyze is complex. The most effective approach is for an experienced professional to build the initial threat model, with AI being used to process and analyze relevant data under human supervision.
AI can process and interpret various types of data, including:
Types of threats
Security controls
Attack surface exposure
Flaws in design
Vulnerabilities in code
Imagine a generative AI tool scaling your security design reviews (SDR) using cutting-edge techniques such as multi-modal retrieval augmented generation (RAG), decision trees and prompt engineering. While it was quite the unthinkable 5 years back, new-age companies like Seezo are making it happen!
Conclusive Note
There is no one-size-fits-all approach to security planning and certain modeling methods may be more effective for some businesses than others. It is essential to have a crystal clear understanding of your current development, IT management, and security operations processes before moving ahead with threat modeling.
If you are looking forward to scale application security programs using generative AI, experts from Seezo can ally with you in this journey and ensure that your applications have a shield as new threats emerge.
Stay ahead in cybersecurity—Sign up for Seezo today and empower your security strategy with the latest in AI-driven threat modeling. Book a demo today!