security-review

name	security-review
description	Threat-model rubric for a focused security review of a code change. Use when reviewing auth / input validation / crypto / secrets / supply chain, or as the "security" dimension of a multi-perspective PR review. Pull this skill before starting so severity calibration and coverage stay consistent.
allowed-tools	["Bash","Read","Glob","Grep"]

Security review procedure

A focused rubric for security review of a code change. Designed as the "security" specialist dimension of a multi-perspective PR review, but applies equally to a standalone audit.

Scope

Review ONLY your assigned diff (or module). Cross-module concerns go to the architecture specialist; correctness bugs without security impact go to correctness.

Checklist summary (10 sections)

1. Authentication & authorization — endpoint auth checks, session tokens, RBAC, fail-closed, multi-tenant
2. Input validation — type/range/length/encoding, parameterization, regex anchoring, structured data parsers
3. Data exposure — error messages, logs, response fields, timing/cache leaks
4. Crypto & secrets — hardcoded keys, safe defaults, weak primitives, random vs secrets, password hashing
5. Injection — SQL, shell, LDAP, template, HTML/XSS
6. File / path handling — path containment, zip-slip, temp files, symlinks
7. Supply chain — typosquatting, pinned versions, endpoint validation
8. Deserialization & parsers — pickle, yaml.load, eval, exec, XXE
9. Race conditions / TOCTOU — atomic file operations, lock scope
10. Denial of service — unbounded loops on user input, rate limiting

See threat-model.md for full per-section detail and CWE mapping.

Severity calibration

• CRITICAL — exploitable now, no special conditions: auth bypass, RCE, full data exposure
• HIGH — data exposure / auth gap requiring specific conditions
• MEDIUM — mis-scoped tokens, weak validation, missing rate limit
• LOW — defense-in-depth hardening
• INFO — notes for future consideration

Rule of thumb: CRITICAL vs HIGH — user action required to exploit? No = CRITICAL, chained = HIGH. HIGH vs MEDIUM — exploitable at attacker's expected access level? Yes = HIGH, needs escalation = MEDIUM.

Output format

Severity	Location	Description	Suggested fix	Confidence	Runtime-context caveats
HIGH	file.py:112	Path not containment-checked	Canonicalize, enforce containment, and use race-resistant access	High	Symlink and TOCTOU handling depends on the later file operation

Verdict at top: APPROVE | REQUEST CHANGES | REJECT. Cite file:line. Reference CWE where clear (CWE-22 path traversal, CWE-89 SQLi).

Ground rules

1. Don't invent requirements.
2. Flag runtime context you need but can't see.
3. Be honest about confidence.
4. Review against committed HEAD of the PR branch.