michaelalber/python-security-review

Python Security Review

"Security is not a product, but a process." — Bruce Schneier

Core Philosophy

Shared across the dotnet / python / php / rust security reviews — same values, language-specific threats.

| # | Value | What it means | |---|-------|---------------| | 1 | Validate at boundaries | Every external input validated and typed at the edge (Pydantic/serializers); never trust client data. | | 2 | Parameterized queries only | No f-string / %-formatted SQL; bound parameters or the ORM everywhere. | | 3 | Secrets out of code | No hardcoded secrets; env / secret-manager; never logged. | | 4 | Authn/authz at every boundary | Authentication and authorization enforced server-side at each trust boundary; deny by default. | | 5 | Least privilege & safe defaults | Minimal permissions; secure defaults; fail closed. | | 6 | Protect data in transit & at rest | No sensitive data (passwords, tokens, PII) in logs; TLS; encryption at rest. | | 7 | Dependencies pinned & audited | Versions pinned; pip-audit in CI; supply chain reviewed. | | 8 | Evidence-based, graded findings | Every finding cites file:line + OWASP category + severity; report is graded and manager-readable. |

Workflow

Shared skeleton: DETECT → SCAN → EXECUTIVE SUMMARY → GRADED FINDINGS.

DETECT     Framework (FastAPI/Django/Flask + version), entry points (routes, views, tasks, CLIs),
           and the data stores / external calls in scope.

SCAN       Walk the Python Threat Checklist below, one OWASP category at a time. Gather evidence:
             bandit -r <pkg>            # static security analysis
             pip-audit                  # known CVEs in dependencies
             grep -rn "yaml.load(\|shell=True\|format(.*SELECT" <pkg>
           Every issue becomes a finding with file:line, OWASP category, and severity.

EXEC SUMMARY  Manager-friendly: risk grade, count by severity, top 3 risks in plain language.

FINDINGS      Technical table: severity · location · OWASP · finding · remediation.

Python Threat Checklist (language-specific)

| OWASP (2025) | Python check | Severity signal | |---|---|---| | A01 Broken Access Control | Auth dependencies/decorators on every protected route; object-level checks (no IDOR); deny by default | Critical | | A02 Cryptographic Failures | hashlib SHA-256+ (never MD5/SHA1 for security); secrets/os.urandom for tokens (not random); passlib/bcrypt for passwords | High | | A03 Injection | ORM or bound params (no f-string/% SQL); no shell-command execution on input (subprocess(..., shell=True), shell helpers); no dynamic eval/exec on input | Critical | | A04 Insecure Design | Server-Side Template Injection (Jinja2 rendering user input); open redirects | High | | A05 Misconfiguration | DEBUG=False in prod; ALLOWED_HOSTS/CORS locked down; secure cookie flags; SECRET_KEY from env | High | | A06 Vulnerable Components | pip-audit clean; versions pinned in pyproject.toml; no abandoned packages | High | | A08 Integrity Failures | No insecure deserialization of untrusted input (native object deserialization, yaml.load without SafeLoader) | Critical | | A09 Logging Failures | No passwords/tokens/PII in logs; auth and access failures logged | Medium | | A10 SSRF | Outbound URLs from user input validated/allow-listed; no raw requests.get(user_url) | High |

Full per-category checklist: owasp python checklist.

State Block

<security-review-state>
language: python
mode: DETECT | SCAN | EXEC-SUMMARY | FINDINGS | COMPLETE
detected: [framework+version | entry points | data stores]
owasp_covered: [A01..A10 progress]
findings: [critical:N high:N medium:N low:N]
last_action: [what was just done]
next_action: [what should happen next]
</security-review-state>

Output Template

Shared across all four security reviews. Executive summary template: executive summary.

## Security Review: [project] (Python)
**Framework**: [FastAPI/Django/Flask] | **Scope**: [paths] | **Risk grade**: [A–F]

### Executive Summary (manager-friendly)
[2–3 sentences: overall posture, the most serious risk in plain language, recommended next step.]
Findings: Critical [N] · High [N] · Medium [N] · Low [N]

### Technical Findings
| Severity | Location | OWASP | Finding | Remediation |
|----------|----------|-------|---------|-------------|
| CRITICAL | file:line | A03 | [pattern] | [fix] |

**Top 3 priorities**: 1. … 2. … 3. …

Risk grade: A no critical/high · B no critical, ≤2 high · C no critical, multiple high · D 1+ critical · F systemic (injection + secrets in code + broken access control).

AI Discipline Rules

• Evidence or it is not a finding. Run bandit/pip-audit; cite file:line and the OWASP category. No speculative findings.
• Detect the framework first. Django escapes templates and ships CSRF; FastAPI validates via Pydantic — confirm these are used, not bypassed, before flagging.
• Severity reflects exploitability + impact, not how unusual the pattern looks.
• Architecture, not here. Structural/maintainability issues belong to python-architecture-checklist — note and route.
• Federal/gov context → escalate. If NIST/FIPS/CUI/DOE applies, run security-review-federal after this base review.

Integration with Other Skills

• security-review-federal — Federal/gov overlay (NIST 800-53, FIPS, CUI, POA&M) applied on top of this base review.
• python-architecture-checklist — Companion for structure/maintainability; run first for context.
• supply-chain-audit — Deeper dependency/CVE and license analysis beyond pip-audit.
• dotnet / php / rust-security-review — Sibling skills sharing this exact Core Values + workflow + output.