Cybersecurity Foundations (Grades 9–12) · lesson 3 of 7 · 15 min
What is threat modeling? Threat modeling is a structured process for identifying security risks before they become incidents. It answers four questions: What are we protecting? Who might attack it? What could go wrong? How do we reduce the risk? STRIDE framework STRIDE is a widely used threat categorization model developed at Microsoft: S — Spoofing: pretending to be someone else (fake login, IP spoofing). T — Tampering: modifying data without authorization. R — Repudiation: denying an action occurred (no audit trail). I — Information disclosure: exposing data to unauthorized parties. D — Denial of service: making a system unavailable. E — Elevation of privilege: gaining higher access than authorized. Data Flow Diagrams Threat modeling starts with a Data Flow Diagram (DFD) — a map of how data moves through a system. You identify trust boundaries (where data crosses from one security zone to another) and apply STRIDE at each boundary.
Threat modeling quiz
An attacker intercepts a login request and replaces the username with an admin account name. Which STRIDE category is this?
- Tampering
- Spoofing
- Repudiation
- Elevation of privilege
Answer: Spoofing
The attacker is pretending to be the admin — that is spoofing (impersonating an identity).
A web app has no logging. An admin deletes records and claims they never did it. Which STRIDE threat does missing logging enable?
- Tampering
- Information disclosure
- Repudiation
- Denial of service
Answer: Repudiation
Without logs, actions cannot be proven — repudiation threats exploit the absence of audit trails.
Previous lesson: Defense in depth
Back to Cybersecurity Foundations (Grades 9–12)
Next lesson: Risk, vulnerability, and threat