# Threat Modeling

## About

Threat modeling is a structured approach to identifying, analyzing, and mitigating potential security threats in a system before they can be exploited. It helps organizations proactively assess risks and design secure systems by evaluating possible attack vectors, weaknesses, and mitigation strategies.

## Why is Threat Modeling Important?

1. **Early Identification of Security Risks** – Helps detect vulnerabilities in the design phase before they become costly to fix.
2. **Improves Security Posture** – Strengthens system defenses by anticipating and addressing threats in advance.
3. **Compliance & Regulatory Requirements** – Helps meet security standards like GDPR, HIPAA, PCI-DSS, and ISO 27001.
4. **Reduces Attack Surface** – Minimizes the number of potential entry points attackers could exploit.
5. **Enhances Risk Management** – Provides insights into the likelihood and impact of security threats.

## Steps in Threat Modeling

### **1. Define the Scope & Objectives**

* Identify the system, application, or process being analyzed.
* Determine security goals and compliance requirements.
* Understand who the potential attackers are and what their motivations might be.

### **2. Understand the System Architecture**

* Document system components, data flow, APIs, and dependencies.
* Identify security boundaries (e.g., internal vs. external networks, user authentication layers).
* Use architecture diagrams to visualize the attack surface.

### **3. Identify Potential Threats**

* Analyze how data moves through the system and where vulnerabilities might exist.
* Identify common attack vectors such as SQL injection, cross-site scripting (XSS), privilege escalation, etc.
* Consider insider threats, social engineering, and misconfigurations.

### **4. Analyze & Prioritize Risks**

* Assess threats based on **likelihood** and **impact** to prioritize mitigation efforts.
* Use risk assessment models like **DREAD** (Damage, Reproducibility, Exploitability, Affected users, Discoverability) or **CVSS** (Common Vulnerability Scoring System).

### **5. Define Mitigation Strategies**

* Apply **security controls** such as authentication mechanisms, encryption, access controls, and monitoring solutions.
* Follow **secure coding practices** to eliminate software vulnerabilities.
* Implement **least privilege** access controls to limit exposure.

### **6. Validate & Test the Threat Model**

* Conduct **penetration testing** and **security audits** to validate findings.
* Use **automated security tools** to simulate attacks.
* Continuously update the threat model as the system evolves.

## Common Threat Modeling Frameworks

### **1. STRIDE Model (Developed by Microsoft)**

STRIDE is a widely used threat categorization framework

<table data-full-width="true"><thead><tr><th width="217">Threat Category</th><th>Description</th><th>Example Attack</th></tr></thead><tbody><tr><td><strong>S</strong>poofing</td><td>Pretending to be another user/system</td><td>Identity theft, phishing</td></tr><tr><td><strong>T</strong>ampering</td><td>Altering data to manipulate outcomes</td><td>Data modification in transit</td></tr><tr><td><strong>R</strong>epudiation</td><td>Performing actions without accountability</td><td>Deleting logs to erase evidence</td></tr><tr><td><strong>I</strong>nformation Disclosure</td><td>Unauthorized access to sensitive data</td><td>Data leakage, API exposure</td></tr><tr><td><strong>D</strong>enial of Service (DoS)</td><td>Disrupting system availability</td><td>Overloading a web server</td></tr><tr><td><strong>E</strong>levation of Privilege</td><td>Gaining unauthorized access rights</td><td>Privilege escalation exploit</td></tr></tbody></table>

### **2. PASTA (Process for Attack Simulation and Threat Analysis)**

A risk-centric methodology for identifying and mitigating threats, typically used in enterprise systems.

### **3. Trike**

A framework focused on risk-based security assessment and access control threats.

### **4. VAST (Visual, Agile, and Simple Threat Modeling)**

Designed for DevOps environments, emphasizing automation and scalability.

## Tools for Threat Modeling

* **Microsoft Threat Modeling Tool** – Automates STRIDE-based threat modeling.
* **OWASP Threat Dragon** – Open-source tool for visualizing threats.
* **IriusRisk** – A collaborative platform for risk analysis.
* **ThreatModeler** – Enterprise-grade automation for large-scale security teams.

## Best Practices for Effective Threat Modeling

1. **Integrate Early in Development** – Apply threat modeling during the design phase rather than after deployment.
2. **Use Automation Where Possible** – Leverage security tools to detect and track threats efficiently.
3. **Involve Cross-Functional Teams** – Include developers, security teams, architects, and business stakeholders.
4. **Continuously Update Threat Models** – Regularly revise models to account for system updates and new threats.
5. **Map Threats to Security Controls** – Ensure every identified threat has a corresponding mitigation strategy.
