Security Threat ModelCAUTION

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The instruction file, verbatim from the audited commit — this is the text the model reads, and the surface the audit's instruction layer examines. Quoted here so you can judge it without cloning anything.

---
name: security-threat-model
description: "Write a STRIDE-based threat model for a service or feature. Use when asked to produce a threat model, document security risks, identify attack vectors, assess a service's security posture, or prepare for a security design review. Produces a structured threat model covering assets, trust boundaries, STRIDE threat enumeration per component, risk scores, mitigation controls, and residual risk sign-off."
---

# Security Threat Model Skill

Produce a complete STRIDE-based threat model for a service or feature. A threat model is not a list of things that could go wrong — it is a structured analysis of attackers, assets, boundaries, and controls that lets an engineering team make informed, documented security decisions.

A good threat model is specific enough that a new engineer can understand what is being protected, why each control exists, and what risk the team has accepted.

## Required Inputs

Ask for these if not already provided:
- **Service name and description** — what the service does, who uses it
- **Architecture overview** — components, dependencies, data flows (a diagram description or ASCII diagram is fine)
- **Deployment environment** — cloud provider, VPC/network topology, where it runs (Kubernetes, ECS, VMs, serverless)
- **Data sensitivity** — what data does this service handle? PII, payment data, credentials, internal-only?
- **Existing controls** — authentication method, encryption in transit/at rest, current WAF/firewall, existing security scanning
- **Trust levels** — who are the principals? (anonymous public, authenticated users, internal services, admins)

## Output Format

---

# Security Threat Model: [Service Name]

**Service:** [Name] | **Team:** [Team name]
**Author:** [Name] | **Reviewed by:** [Security lead / peer]
**Date:** [Date] | **Next review:** [Date — recommend 6 months or after major architecture change]
**Classification:** [Internal / Confidential]

---

## 1. Overview

[2–3 sentences describing the service, its role in the system, and the scope of this threat model. State what is in scope and what is explicitly out of scope.]

**In scope:**
- [Component or data flow]
- [Component or data flow]

**Out of scope:**
- [e.g. Third-party payment processor internals]
- [e.g. Corporate network / end-user devices]

---

## 2. Asset Register

Assets are the things worth protecting — data, capabilities, and reputational value.

| Asset | Description | Sensitivity | Owner |
|---|---|---|---|
| [e.g. User PII] | Names, email addresses, profile data | High — GDPR-regulated | [Team] |
| [e.g. API credentials] | Service-to-service auth tokens | Critical | [Team] |
| [e.g. Session tokens] | User authentication state | High | [Team] |
| [e.g. Audit logs] | Record of user and admin actions | Medium | [Team] |
| [e.g. Service availability] | Uptime of the [X] endpoint | Medium | [Team] |

**Data classification key:**
- **Critical** — Credential material; exposure enables direct system compromise
- **High** — PII, financial data, health data; regulated or high reputational impact
- **Medium** — Internal configuration, non-sensitive business data
- **Low** — Public information, anonymised data

---

## 3. Trust Boundaries and Architecture

Trust boundaries are the lines that separate zones with different trust levels. Threats often occur when data or requests cross a boundary.

```
  ┌─────────────────────────────────────────────────────────────────┐
  │  INTERNET (Untrusted)                                           │
  │                                                                 │
  │   [Public User]          [Bot / Attacker]                       │
  └──────────────────────────────┬──────────────────────────────────┘
                                 │ HTTPS
                    ─ ─ ─ ─ ─ ─ ─│─ ─ ─ ─ ─ ─ ─ ─
                    Trust Boundary: Public → DMZ
                    ─ ─ ─ ─ ─ ─ ─│─ ─ ─ ─ ─ ─ ─ ─
                                 ▼
  ┌──────────────────────────────────────────────────────────────────┐
  │  DMZ / Edge Layer                                                │
  │   ┌────────────┐     ┌──────────────┐                           │
  │   │  WAF / CDN │────▶│  API Gateway │                           │
  │   └────────────┘     └──────┬───────┘                           │
  └──────────────────────────────┼───────────────────────────────────┘
                    ─ ─ ─ ─ ─ ─ ─│─ ─ ─ ─ ─ ─ ─ ─
                    Trust Boundary: Edge → Application VPC
                    ─ ─ ─ ─ ─ ─ ─│─ ─ ─ ─ ─ ─ ─ ─
                                 ▼
  ┌──────────────────────────────────────────────────────────────────┐
  │  Application VPC (Private)                                       │
  │   ┌──────────────┐     ┌────────────┐     ┌──────────────────┐  │
  │   │  [Service A] │────▶│ [Service B]│────▶│  [Database]      │  │
  │   └──────────────┘     └────────────┘     └──────────────────┘  │
  │                                ▲                                  │
  │                                │                                  │
  │   ┌──────────────┐             │                                  │
  │   │  Admin (IAM) │─────────────┘                                 │
  └──────────────────────────────────────────────────────────────────┘
```

**Trust Boundaries identified:**

| Boundary | From | To | Auth mechanism | Encrypted |
|---|---|---|---|---|
| TB-1 | Public internet | API Gateway | [JWT / OAuth / API key] | TLS 1.2+ |
| TB-2 | API Gateway | Service A | [mTLS / internal JWT / IAM role] | [Yes/No] |
| TB-3 | Service A | Database | [Connection string + IAM / username+password] | [Yes/No] |
| TB-4 | Admin | Service B | [IAM role / VPN + MFA] | TLS |

---

## 4. STRIDE Threat Analysis

STRIDE is a threat classification framework. For each significant component, enumerate threats in each category.

**STRIDE key:**
- **S** — Spoofing: Impersonating another user, service, or system
- **T** — Tampering: Modifying data or

CAUTIONgrade B · trust 89/100 Install with care. The audit found things worth knowing before you trust its output.

What the source does

Filesystem

none-observed

Network

none-observed

Shell

none-observed

Dependencies

pinned

Secrets in source

none-found

Findings (5)

templates/pm-discovery-agent/skills/assumption-mapper/SKILL.md

templates/pm-discovery-agent/skills/discovery-interview-guide/SKILL.md

templates/pm-discovery-agent/skills/job-story-mapper/SKILL.md

templates/pm-discovery-agent/skills/user-interview-synthesis/SKILL.md

templates/pm-launch-agent/skills/content-calendar/SKILL.md

Gates applied: no_behavioural_pass.