magnus919_agent-skills/security-audit-methodology/SKILL.md

name, description, license, compatibility, metadata

name	description	license	compatibility	metadata
security-audit-methodology	Plan authorized security reviews with threat modeling, architecture and dependency audits, and vulnerability classification. Use for scoped defensive security assessment.	MIT	Authorization for the target system is required. This skill provides defensive methodology, not a substitute for qualified security review.	source_repo source_commit https://github.com/magnus919/hermes-profiles 867a555

Security Audit Methodology

Authorization and safety boundary

Before any assessment, confirm the target, scope, permitted techniques, data-handling rules, and escalation contact. Do not probe systems, access accounts, exploit findings, or alter production state without explicit authorization. Record findings as evidence for the responsible owner; this skill does not certify compliance or replace qualified security review.

Security is not a checklist — it's a posture. This methodology covers systematic evaluation of code, architecture, dependencies, and operational practices for security weaknesses.

The Security Engineer's Domain

You own	You don't own
Threat modeling — STRIDE, attack trees, trust boundaries	General code review — that's the reviewer
Vulnerability assessment — classification, severity, reproduction	Performance analysis — that's the debugger
Security architecture review — authn/authz, data flow, secrets management	Operational reliability — that's SRE
Dependency analysis — supply chain, known vulnerabilities, license risk	Compliance certification — that's legal
Security testing guidance — fuzzing, SAST/DAST integration	Incident response execution — that's SRE/on-call

Reference Files

Reference	When to load
references/threat-modeling.md	Evaluating a system's attack surface — STRIDE per component, trust boundaries, data flow analysis
references/vulnerability-classification.md	Assessing a finding — CVSS scoring, CWE mapping, severity triage, exploitability assessment
references/security-architecture-dependency-audit.md	Reviewing authentication (OAuth 2.0, OIDC, SAML, mTLS), authorization (RBAC/ABAC/ReBAC), session management, secrets management, and dependency/supply chain security (SBOM, CVE matching, license analysis, SLSA framework)

Core Principles

Trust nothing, verify everything — Every input, every boundary, every assumption is a potential attack surface. Default deny, explicit allow.

Defense in depth — No single control is sufficient. Authentication without rate limiting, encryption without key management, input validation without output encoding — each is a vulnerability waiting to chain.

Least privilege — Every component, every user, every process should have exactly the permissions it needs and no more. Over-privilege is the most common security debt.

Understand the attacker's perspective — The question isn't "can this be exploited?" It's "how would an attacker think about this system?" Model their incentives, constraints, and capabilities.

Fix the class, not the instance — One SQL injection means you need parameterized queries everywhere, not just at that one endpoint. A single XSS means review the entire rendering pipeline.

Portability

This skill is intentionally host-neutral. Use your agent's normal mechanisms to load the references, templates, and scripts listed here. Do not assume a particular profile system, task orchestrator, memory service, or response-handoff format.