Creating an effective threat model with OWASP Threat Dragon involves systematically identifying and mapping actors, processes, and trust boundaries within your web application.
Here's how to approach each element:
1. Identify and Define Actors
Actors are entities that interact with your system, including users, external systems, and internal components. To define them:
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List All Interacting Entities: Identify who or what interacts with your application. This includes end-users, administrators, third-party services, and internal modules.
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Categorize Actors: Classify actors based on their roles and access levels, such as regular users, privileged users, or external APIs.
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Determine Objectives and Motivations: Understand what each actor aims to achieve to assess potential threats from their interactions.
2. Map Processes
Processes represent the operations and data flows within your application. To map them effectively:
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Break Down the Application: Decompose your application into functional components and workflows.
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Illustrate Data Flows: Use data flow diagrams to show how data moves between components, highlighting inputs, processing steps, and outputs.
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Identify Entry and Exit Points: Pinpoint where data enters and exits the system, as these are critical areas for security analysis.
3. Establish Trust Boundaries
Trust boundaries delineate areas with different levels of trust, indicating where data transitions between these areas. To establish them:
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Identify Security Domains: Determine zones within your application that have varying trust levels, such as internal networks, demilitarized zones (DMZs), and external networks.
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Mark Data Transitions: Highlight where data crosses from one trust level to another, as these transitions are potential vulnerability points.
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Assess Access Controls: Ensure appropriate security measures are in place at each trust boundary to regulate data flow and access.
Best Practices for Using OWASP Threat Dragon
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Leverage Built-in Templates: Threat Dragon offers templates and predefined elements to streamline the modeling process.
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Iterative Refinement: Regularly update and refine your threat model to reflect changes in the application architecture or threat landscape.
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Collaborative Approach: Engage cross-functional teams, including developers, security experts, and business stakeholders, to gain diverse insights.
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Document Assumptions and Decisions: Keep detailed records of the assumptions made and decisions taken during the modeling process for future reference.
Handling Complex Architectures
For intricate systems:
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Modular Modeling: Divide the system into smaller, manageable modules, and create separate threat models for each before integrating them.
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Use Hierarchical Diagrams: Employ hierarchical data flow diagrams to represent different abstraction levels, facilitating a clearer understanding of complex interactions.
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Prioritize Critical Components: Focus on high-risk areas first, such as components handling sensitive data or those exposed to external interactions.
