Every security measure exists to stop something. Before writing a single line of defensive code, a security-aware designer asks a simple question: what could go wrong here? That question — asked systematically — is threat modeling.
The OWASP Top 10 lists A04:2021 - Insecure Design as its own category to make a point clear. Most vulnerabilities are implementation defects — a missing check, a bad query. An insecure design is different: the flaw is in the plan itself, and no amount of careful coding can patch it away. A checkout that trusts a client-supplied price can be bug-free and still let a customer buy a laptop for one cent.
In this lesson you will:
- Learn the six STRIDE threat categories and the security property each one breaks.
- Classify concrete scenarios into STRIDE categories.
- Review the secure-design principles that turn a threat model into a safer architecture.
Estimated time: 10 to 15 minutes. This is a reflective, design-focused lesson; there is no offensive payload to run against the application.
When you are ready, send the Continue signal.