🛡️ Threat Modeling

Definition:

Threat modeling is the process of identifying, analyzing, and mitigating potential security threats to a system before they occur.

It’s a proactive approach to secure system design.

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1️⃣ Why Threat Modeling is Important

• Helps identify security risks early in design/development.
• Prioritizes critical threats based on risk.
• Guides mitigation strategies to protect data, users, and infrastructure.
• Reduces cost and effort compared to fixing vulnerabilities post-deployment.

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2️⃣ Key Components

1. Assets:

   • What are you protecting?
   • Examples: user data, financial transactions, internal APIs.

2. Entry Points / Attack Surfaces:

   • Where can attackers interact with the system?
   • Examples: web forms, APIs, admin portals, database endpoints.

3. Threats:

   • What can go wrong?
   • Examples: SQL injection, XSS, privilege escalation, data exfiltration.

4. Vulnerabilities:

   • Weaknesses that could be exploited by threats.
   • Example: unvalidated input, default passwords, outdated libraries.

5. Mitigations / Controls:

   • How to prevent, detect, or respond to threats.
   • Examples: input validation, encryption, multi-factor authentication, firewalls.

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3️⃣ Common Threat Modeling Approaches

Approach	Description
STRIDE	Focuses on threat types: Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, Elevation of Privilege
PASTA (Process for Attack Simulation & Threat Analysis)	Risk-centric, iterative modeling to simulate attacks
OCTAVE	Organizational risk and asset-based threat modeling
Attack Trees	Graphical tree of potential attack paths and mitigations

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4️⃣ Steps in Threat Modeling

1. Define scope and assets
2. Diagram the system (data flow, components, interactions)
3. Identify threats and vulnerabilities
4. Prioritize risks (e.g., impact vs likelihood)
5. Define mitigation strategies
6. Review & iterate regularly

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5️⃣ Example: Web Application Threat Modeling

Step 1: Assets → User data, payment info Step 2: Entry points → Login page, API endpoints Step 3: Threats → SQL Injection, XSS, brute-force login Step 4: Vulnerabilities → No input validation, weak passwords Step 5: Mitigations → Input validation, rate limiting, MFA Step 6: Monitor → Logs, alerts, periodic review

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💡 Analogy:

Think of threat modeling like planning security for a bank:

• Identify valuables → vaults, cash, customer info
• Identify entrances → doors, windows, staff access
• Identify potential attacks → burglary, insider theft
• Plan mitigations → alarms, cameras, guards

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