{"slug":"sota-threat-modeling","title":"sota-threat-modeling","summary":"State-of-the-art threat modeling for both designing new systems and auditing existing ones. Use when designing a feature, service, integration, or architecture that touches untrusted input, new trust boundaries, sensitive data, or third-party dependencies (BUILD mode), and when r","platform":"Claude","tags":[],"authorName":"LLM Mart","authorSlug":"llm-mart","score":0,"source":"github","price":null,"verified":false,"createdAt":"2026-09-09T18:38:51.268477Z","repo":{"url":"https://github.com/martinholovsky/SOTA-skills","stars":23,"forks":2,"license":"CC-BY-4.0","updatedAt":"2026-09-27T16:35:16Z"},"bodyHtml":"
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name: sota-threat-modeling\ndescription: >-\nState-of-the-art threat modeling for both designing new systems and auditing\nexisting ones. Use when designing a feature, service, integration, or\narchitecture that touches untrusted input, new trust boundaries, sensitive\ndata, or third-party dependencies (BUILD mode), and when reviewing, auditing,\nor pen-test-scoping an existing codebase to reconstruct its implicit threat\nmodel and find gaps (AUDIT mode). Not for code-level vulnerability review —\nuse sota-code-security. Trigger keywords: threat model, STRIDE,\nLINDDUN, PASTA, attack tree, kill chain, data flow diagram, DFD, trust\nboundary, attack surface, abuse case, security design review, security\narchitecture review, risk rating, DREAD, CVSS, security requirements,\nsecure design, security audit, gap analysis, prompt injection, excessive\nagency, threat catalog, mitigations, residual risk.

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SOTA Threat Modeling

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Purpose

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Threat modeling answers Shostack's four questions with engineering rigor:

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    \n
  1. What are we working on? (decompose: DFD, trust boundaries, assets, actors)
    2. \n
  2. What can go wrong? (enumerate: STRIDE/LINDDUN per element, catalogs, attack trees)
    3. \n
  3. What are we going to do about it? (treat: mitigate/accept/transfer/avoid, map to requirements and tests)
    4. \n
  4. Did we do a good job? (verify: abuse-case tests, residual risk review, re-model triggers)
    5. \n
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This skill operationalizes those questions in two modes. Never produce a threat\nmodel that is only prose — every threat must land as a tracked requirement, a\ntest, or an explicitly accepted risk with an owner.

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BUILD Mode — Threat-Model-While-Designing

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Run this workflow whenever designing anything that crosses a trust boundary.\nScale effort to risk: a 15-minute \"four questions\" pass for a small feature; a\nfull STRIDE-per-interaction model for a new service or auth flow.

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Workflow

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  1. Scope the delta. Model what is new or changed, not the whole system.\nList new entry points, new data classes, new dependencies, new actors.
    2. \n
  2. Draw the DFD as text/mermaid (see rules/02). Mark trust boundaries\nexplicitly. If you cannot draw a boundary, you do not understand the design\nyet — stop and ask.
    3. \n
  3. Pick the methodology (see rules/01): STRIDE-per-interaction by\ndefault; add LINDDUN if personal data flows; attack trees for a single\nhigh-value asset; four-questions-only for low-risk deltas.
    4. \n
  4. Enumerate threats crossing each boundary using the per-component\ncatalogs in rules/03. Write each threat as: actor → action → asset →\nimpact. No vague entries (\"hacking\", \"data breach\").
    5. \n
  5. Rate and treat each threat (see rules/04): likelihood × impact matrix,\nthen accept / mitigate / transfer / avoid. Every mitigation becomes a\nsecurity requirement with an ID.
    6. \n
  6. Emit artifacts (see rules/05): threat model doc, security requirements\nbacklog entries, abuse cases as test stubs, and re-modeling triggers.
    7. \n
  7. Wire into delivery. Reference requirement IDs in the design doc, tickets,\nand PR descriptions. A threat without a tracked artifact does not exist.
    8. \n
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Continuous / incremental (agile, PR reviews)

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AUDIT Mode — Reconstructing a Threat Model from Code

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Use when handed an existing system with no (trustworthy) threat model. Goal:\nrebuild the implicit model from artifacts, then diff intended vs. actual\ncontrols. Full procedure in rules/06.

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Workflow

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  1. Inventory entry points from code (see rules/02 §extraction): routes,\nqueue consumers, cron jobs, webhooks, third-party callbacks, CLI/admin\ntools, file uploads, IaC-exposed ports.
    2. \n
  2. Reconstruct the DFD from the inventory: processes, stores, external\nentities, flows; infer trust boundaries from network topology, authn\ncheckpoints, and IAM policies.
    3. \n
  3. Identify assets and actors from schemas, secrets handling, and config.
    4. \n
  4. Run the catalogs (rules/03) against each component; for every catalog\nitem record: control present / absent / partial, with file:line evidence.
    5. \n
  5. Gap analysis: rank absent/partial controls by exploitability ×\nblast radius; distinguish \"missing control\" from \"missing defense-in-depth\".
    6. \n
  6. Report findings in the standard format below.
    7. \n
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Severity conventions

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
SeverityDefinition
CriticalRemotely exploitable now, by an unauthenticated or low-priv actor, leading to full compromise of a key asset (RCE, auth bypass, mass data exfil). Fix before anything else ships.
HighExploitable with realistic preconditions (one valid account, one misconfig, MitM position) compromising a key asset; or a Critical with a single weak mitigating layer. Fix this sprint.
MediumRequires chaining, elevated access, or unusual conditions; or impacts a secondary asset; or defense-in-depth gap on a Critical path. Schedule.
LowHardening, hygiene, info disclosure of low-value data, theoretical with strong existing controls. Backlog.
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Severity = exploitability × impact in this deployment context — never copy\na CVE/CVSS base score without environmental adjustment (see rules/04).

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Finding format (every finding, no exceptions)

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[SEV] TITLE (component, STRIDE/LINDDUN class)\nLocation: path/to/file.py:123 (and IaC/config refs)\nThreat: <actor> can <action> via <vector> because <missing/weak control>,\n        impacting <asset> (<C/I/A/privacy impact>).\nEvidence: code excerpt or config line proving the gap.\nRecommendation: specific control + where it goes; map to requirement ID.\nResidual risk if accepted: one sentence.\n
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Rules Index

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FileRead this when...
rules/01-methodologies.mdChoosing between STRIDE, LINDDUN, PASTA, attack trees, kill chains; deciding lightweight vs. heavyweight; setting up continuous/PR-level threat modeling.
rules/02-decomposition.mdDrawing DFDs in mermaid, defining trust boundaries, listing entry points/assets/actors/privilege levels; extracting all of these from an existing codebase.
rules/03-threat-catalogs.mdEnumerating threats for a specific component: web frontend, API, database, message queue, file storage, CI/CD, mobile, LLM agent/tool-use, cloud/IAM.
rules/04-risk-rating-treatment.mdRating threats (DREAD pitfalls, CVSS usage, L×I matrices), choosing accept/mitigate/transfer/avoid, mapping mitigations to requirements and tests, documenting residual risk.
rules/05-outputs-operationalization.mdWriting the threat model document, building the security requirements backlog, turning abuse cases into tests, keeping the model alive (re-model triggers).
rules/06-audit-reconstruction.mdAuditing an existing system: reconstructing the model from code, control-presence matrix, gap analysis, severity calibration, reporting.
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Load only the files you need; rules/02 + rules/03 cover 80% of day-to-day work.

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Top-10 Non-Negotiables

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  1. No model without a diagram. Every threat model includes a DFD (mermaid\nor ASCII) with explicit trust boundaries. Prose-only models hide boundary\nconfusion.
    2. \n
  2. Threats are sentences, not nouns. Actor → action → asset → impact.\n\"SQL injection\" is a vector; \"anonymous user exfiltrates the orders table\nvia unparameterized search query\" is a threat.
    3. \n
  3. Every entry point gets enumerated — including queues, cron, webhooks,\ncallbacks, admin tooling, and CI/CD. HTTP routes are never the whole attack\nsurface.
    4. \n
  4. Trust boundary crossings drive enumeration. Apply STRIDE per\ninteraction at each crossing; data inside one boundary at one privilege\nlevel rarely needs the full treatment.
    5. \n
  5. Personal data ⇒ LINDDUN pass. STRIDE does not cover linkability,\nidentifiability, or non-compliance; run a privacy pass whenever PII flows\nor is stored.
    6. \n
  6. Rate with likelihood × impact in context. Never ship raw DREAD scores\nor unadjusted CVSS base scores as priorities.
    7. \n
  7. Every threat gets a disposition. Mitigate (→ requirement ID + test),\naccept (→ named owner + expiry date), transfer, or avoid. \"Noted\" is not a\ndisposition.
    8. \n
  8. Mitigations become tests. Each mitigated threat yields at least one\nabuse-case test (unit, integration, or rule-based check) that fails if the\ncontrol regresses.
    9. \n
  9. LLM/agent components are first-class attack surface. Model prompt\ninjection, tool-call abuse, excessive agency, and data exfil via outputs\nfor any system invoking an LLM with tools or retrieved content.
    10. \n
  10. Models expire. Define re-model triggers (new dependency, new trust\nboundary, new data class, auth change) in the document itself; an undated,\ntrigger-less threat model is treated as absent in audits.
    11. \n
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