| name | stride-threat-model |
| description | Use when the operator asks for a STRIDE threat model, security review of an architecture, or asks "what could go wrong" about a system design. Wraps the structured STRIDE methodology and produces an actionable threat register. |
STRIDE threat model
STRIDE = Spoofing, Tampering, Repudiation, Information Disclosure, DoS, Elevation of Privilege.
Inputs you need
- System diagram — components + data flows + trust boundaries. ASCII/mermaid is fine.
- Asset inventory — what's worth attacking (data, accounts, infra).
- Trust model — who is trusted at each boundary.
- Existing controls — auth, encryption, monitoring, segmentation.
If any input is missing, ask one sharp question. Don't guess.
Method
- Decompose the system into components and data flows. Mark trust boundaries explicitly.
- For each component AND each flow, walk all six STRIDE categories. Generate threats.
- For each threat: rate likelihood (low/med/high) × impact (low/med/high) → priority.
- Map controls (existing + recommended). Identify gaps.
- Output a threat register + Cortex/PANW-style summary.
Output template
# Threat Model — <system>
**Date:** <YYYY-MM-DD> **Reviewer:** Henry **Spec version:** <ref>
## Executive summary
<one paragraph, business language, names top 3 risks + recommended action>
## Architecture (decomposed)
```mermaid
<component diagram with trust boundaries>
Threat register
| ID | Component | Category | Threat | Likelihood | Impact | Priority | Existing control | Recommended control |
|---|
| T-001 | API gateway | Spoofing | ... | M | H | P1 | mTLS to backend | Add JWT iss/aud validation |
Recommended detections (Cortex XSIAM/XDR)
- T-001: XQL rule sketch:
dataset = http_logs | filter ...
- ...
Open questions
## Defaults
- Default to **high-impact, plausibly-likely** threats. Don't pad with theoretical exotics unless the ask is explicitly comprehensive.
- For Cortex/PANW pre-sales: every threat that maps to an XSIAM/XDR detection should include the rule sketch.
- Use mermaid for the architecture diagram. Keep it under 15 nodes.
