Guide Threat modeling • critical workflows • mitigations
Threat modeling: keep it simple, keep it useful.
Threat modeling should produce engineering work: tests, guardrails, and design decisions that reduce risk. This guide focuses on practical workflows and repeatable artifacts.
Guide
A practical threat modeling loop
Focus on the workflows that matter, and ship mitigations as engineering changes.
1. Pick one workflow
Choose a workflow that can cause business impact.
- Authentication and session lifecycle
- Payments, payouts, refunds, and admin changes
- Data export, reporting, or bulk access paths
2. Draw the data flow (fast)
You need a useful picture, not a perfect diagram.
- Actors: user/admin/support/service account
- Entry points: web, API, mobile, internal tools
- Trust boundaries: auth, network, tenant boundaries, third parties
3. Identify attack paths
Ask “how would this break?” and “what would the impact be?”
- Abuse cases: replay, privilege escalation, IDOR, session fixation
- Integration risks: webhook abuse, signature validation, key handling
- Admin tooling: support overrides and approval paths
4. Decide mitigations and assign owners
Mitigations must turn into real work with an owner and a due date.
- Prevent: authorization checks, step-up auth, rate limiting
- Detect: audit logs and high-signal alerts for sensitive actions
- Recover: rollback plans and evidence capture
5. Convert mitigations into guardrails
Make good behavior the default.
- Tests: regression tests for authorization and abuse cases
- Checklists: secure design review for new workflows
- CI guardrails: secrets checks, dependency checks, policy-as-code
6. Review on cadence
Threat models should evolve as the system evolves.
- Review after major feature launches
- Review after incidents or high-severity findings
- Review quarterly for critical workflows
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