/stride

name: stride
description: >-
  Run a STRIDE threat model over a system: build/ingest a DFD, then enumerate
  Spoofing, Tampering, Repudiation, Information disclosure, Denial of service,
  and Elevation of privilege threats per element and trust-boundary crossing,
  with mitigations. Use when threat modeling an application, service, or design.

Goal

A STRIDE threat model: each DFD element and trust-boundary crossing examined for the six threat classes, threats recorded with risk, and each mapped to a mitigation.

STRIDE ↔ property

| Threat | Violates | Typical mitigation theme | | --- | --- | --- | | **S**poofing | Authentication | Strong authn, MFA, mutual TLS, signed tokens | | **T**ampering | Integrity | Input validation, signing, integrity checks, least privilege writes | | **R**epudiation | Non-repudiation | Audit logging, tamper-evident logs, timestamps | | **I**nformation disclosure | Confidentiality | Encryption in transit/at rest, authz, data minimization | | **D**enial of service | Availability | Rate limiting, quotas, autoscaling, timeouts | | **E**levation of privilege | Authorization | Least privilege, authz checks, sandboxing, segmentation |

Steps

1. **Get the DFD.** If none exists, invoke `security-diagramming:threat-model-dfd` first. Confirm elements (external entities, processes, data stores, flows) and trust boundaries. 2. **Per element/flow, walk all six letters.** Focus on **trust-boundary crossings** — that's where threats concentrate. Apply only the letters that make sense for the element type (e.g. data stores rarely "spoof"). 3. **Record each threat**: ID · element · STRIDE class · description · preconditions. 4. **Rank** with `/threat-modeling:risk-rank` (likelihood × impact). 5. **Map mitigations** per threat; note existing controls vs. gaps. 6. Optionally model the top threats as attack trees (`security-diagramming:attack-tree`).

Output

A STRIDE table (element · STRIDE class · threat · risk · mitigation · status) plus a short "top risks & recommended controls" summary. Hand to `security-reporting` if a formal document is needed.

Notes

Don't force all six letters onto every element — apply per element type. Tie each threat to a real data flow so it's concrete and testable.