Security Reviewer

Security Reviewer

A pragmatic AppSec review pass for any modern stack. Output is short, severity-ranked findings with file paths, evidence, and a concrete fix — never a 30-page "report".

When to run

Run on any of:

• New HTTP route, RPC handler, or queue consumer
• Auth, session, RBAC, or tenant-isolation change
• Frontend rendering / templating change (XSS surface)
• Outbound HTTP, file fetch, or URL handling (SSRF surface)
• Database query change (injection / IDOR surface)
• Dependency manifest change or lockfile bump
• Config / IaC change (CORS, headers, CSP, IAM, secrets)
• End of a major feature, pre-release, or before opening a PR labelled security-sensitive

If unsure, run it. False positives are cheap; missed CVEs are not.

Eight-point check (language-agnostic)

These eight categories drive every review. Every finding maps to one.

1. Authn/Authz — every route has explicit auth + role/tenant checks; no implicit "logged-in means allowed"
2. Output encoding — all user-influenced HTML/markdown/JSON/log output is encoded for its sink
3. SSRF & outbound HTTP — URL allow-listed, redirects bounded, IMDS / link-local / RFC1918 blocked unless intentional
4. Secrets & key material — no client-side storage, no hardcoded keys, no secrets in URLs or logs
5. Input handling — parameterised queries, path containment, redirect target validation, deserialisation guards
6. Config & headers — CSP, HSTS, X-Content-Type-Options, secure cookies, CORS allowlist, rate limits, dev-bypass off in prod
7. Supply chain — dependencies pinned, lockfile committed, manifest scanned, no unknown registries, install scripts reviewed
8. Failure modes — fail-closed on auth/policy errors, no broad except/catch, errors don't leak stack traces or PII

Routing

When language is known, load the matching reference and use its diagnostic patterns. When mixed, run all relevant ones.

| Detected from… | Read… | |---|---| | pyproject.toml, requirements*.txt, Pipfile, setup.py | languages/python.md | | package.json, *.ts, *.tsx, *.js, *.jsx | languages/javascript-typescript.md | | go.mod | languages/go.md | | Cargo.toml | languages/rust.md | | pom.xml, build.gradle*, *.kt, *.java | languages/java.md | | Gemfile, *.rb | languages/ruby.md | | *.csproj, *.sln, *.cs | languages/dotnet.md |

Then consult the cross-cutting checklists:

• checklists/owasp-asvs.md — OWASP Top 10 (2021) and ASVS L1 controls keyed to the eight-point check
• checklists/endpoint-checklist.md — per-endpoint review template
• playbooks/triage.md — what to do once a finding fires (severity rubric, fix templates, follow-up tickets)

Output format

Every review emits a finding list. Nothing else.

[SEVERITY] 
File:     :
Category: 
Evidence: 
Fix:      
Refs:     

Severities: CRITICAL (auth bypass, RCE, secret leak in prod), HIGH (data exposure, SSRF to internal, missing CSRF on state change), MEDIUM (weak crypto choice, missing rate limit, stack trace leak), LOW (defence-in-depth, hygiene).

If nothing fires, say so explicitly and list residual risks or untested areas — silence is not a clean bill.

Hook integration

Three hooks ship with this skill (/.claude/hooks/):

• session-start.sh — fingerprints the project on session open, runs a fast dependency audit if tooling is present, and injects a security-context block so every agent in the session starts informed.
• pre-bash-package-guard.sh — gates package-manager invocations (npm/yarn/pnpm/pip/uv/poetry/cargo/go get/gem/bundle/composer/dotnet add). Blocks installs of typosquatted, brand-new, or known-malicious packages; prompts for confirmation on borderline cases.
• post-edit-quickscan.sh — runs a fast pattern scan on files touched by Edit/Write/MultiEdit and feeds findings back to the agent that made the change.

Subagents that consume this skill should treat the ## SECURITY CONTEXT block (when injected by session-start.sh) as authoritative project metadata.

Author / provenance

Maintained by Phoenix Security as part of the Phoenix developer-tooling kit. Pairs with phoenix-final-gate (spec-pipeline review) and opengrep-rule-generator (rule synthesis from findings).

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Security-Phoenix-demo
• Source: Security-Phoenix-demo/security-skills-claude-code
• License: MIT

Install and usage instructions live in the source repository linked above.