williamlimasilva/security-review

Security Review

An AI-powered security scanner that reasons about your codebase the way a human security researcher would — tracing data flows, understanding component interactions, and catching vulnerabilities that pattern-matching tools miss.

When to Use This Skill

Use this skill when the request involves:

• Scanning a codebase or file for security vulnerabilities
• Running a security review or vulnerability check
• Checking for SQL injection, XSS, command injection, or other injection flaws
• Finding exposed API keys, hardcoded secrets, or credentials in code
• Auditing dependencies for known CVEs
• Reviewing authentication, authorization, or access control logic
• Detecting insecure cryptography or weak randomness
• Performing a data flow analysis to trace user input to dangerous sinks
• Any request phrasing like "is my code secure?", "scan this file", or "check my repo for vulnerabilities"
• Running /security-review or /security-review <path>

How This Skill Works

Unlike traditional static analysis tools that match patterns, this skill:

1. Reads code like a security researcher — understanding context, intent, and data flow
2. Traces across files — following how user input moves through your application
3. Self-verifies findings — re-examines each result to filter false positives
4. Assigns severity ratings — CRITICAL / HIGH / MEDIUM / LOW / INFO
5. Proposes targeted patches — every finding includes a concrete fix
6. Requires human approval — nothing is auto-applied; you always review first

Execution Workflow

Follow these steps in order every time:

Step 1 — Scope Resolution

Determine what to scan:

• If a path was provided (/security-review src/auth/), scan only that scope
• If no path given, scan the entire project starting from the root
• Identify the language(s) and framework(s) in use (check package.json, requirements.txt, go.mod, Cargo.toml, pom.xml, Gemfile, composer.json, etc.)
• Read references/language-patterns.md to load language-specific vulnerability patterns

Step 2 — Dependency Audit

Before scanning source code, audit dependencies first (fast wins):

• Node.js: Check package.json + package-lock.json for known vulnerable packages
• Python: Check requirements.txt / pyproject.toml / Pipfile
• Java: Check pom.xml / build.gradle
• Ruby: Check Gemfile.lock
• Rust: Check Cargo.toml
• Go: Check go.sum
• Flag packages with known CVEs, deprecated crypto libs, or suspiciously old pinned versions
• Read references/vulnerable-packages.md for a curated watchlist

Step 3 — Secrets & Exposure Scan

Scan ALL files (including config, env, CI/CD, Dockerfiles, IaC) for:

• Hardcoded API keys, tokens, passwords, private keys
• .env files accidentally committed
• Secrets in comments or debug logs
• Cloud credentials (AWS, GCP, Azure, Stripe, Twilio, etc.)
• Database connection strings with credentials embedded
• Read references/secret-patterns.md for regex patterns and entropy heuristics to apply

Step 4 — Vulnerability Deep Scan

This is the core scan. Reason about the code — don't just pattern-match. Read references/vuln-categories.md for full details on each category.

Injection Flaws

• SQL Injection: raw queries with string interpolation, ORM misuse, second-order SQLi
• XSS: unescaped output, dangerouslySetInnerHTML, innerHTML, template injection
• Command Injection: exec/spawn/system with user input
• LDAP, XPath, Header, Log injection

Authentication & Access Control

• Missing authentication on sensitive endpoints
• Broken object-level authorization (BOLA/IDOR)
• JWT weaknesses (alg:none, weak secrets, no expiry validation)
• Session fixation, missing CSRF protection
• Privilege escalation paths
• Mass assignment / parameter pollution

Data Handling

• Sensitive data in logs, error messages, or API responses
• Missing encryption at rest or in transit
• Insecure deserialization
• Path traversal / directory traversal
• XXE (XML External Entity) processing
• SSRF (Server-Side Request Forgery)

Cryptography

• Use of MD5, SHA1, DES for security purposes
• Hardcoded IVs or salts
• Weak random number generation (Math.random() for tokens)
• Missing TLS certificate validation

Business Logic

• Race conditions (TOCTOU)
• Integer overflow in financial calculations
• Missing rate limiting on sensitive endpoints
• Predictable resource identifiers

Step 5 — Cross-File Data Flow Analysis

After the per-file scan, perform a holistic review:

• Trace user-controlled input from entry points (HTTP params, headers, body, file uploads) all the way to sinks (DB queries, exec calls, HTML output, file writes)
• Identify vulnerabilities that only appear when looking at multiple files together
• Check for insecure trust boundaries between services or modules

Step 6 — Self-Verification Pass

For EACH finding:

1. Re-read the relevant code with fresh eyes
2. Ask: "Is this actually exploitable, or is there sanitization I missed?"
3. Check if a framework or middleware already handles this upstream
4. Downgrade or discard findings that aren't genuine vulnerabilities
5. Assign final severity: CRITICAL / HIGH / MEDIUM / LOW / INFO

Step 7 — Generate Security Report

Output the full report in the format defined in references/report-format.md.

Step 8 — Propose Patches

For every CRITICAL and HIGH finding, generate a concrete patch:

• Show the vulnerable code (before)
• Show the fixed code (after)
• Explain what changed and why
• Preserve the original code style, variable names, and structure
• Add a comment explaining the fix inline

Explicitly state: "Review each patch before applying. Nothing has been changed yet."

Severity Guide

| Severity | Meaning | Example | |----------|---------|---------| | 🔴 CRITICAL | Immediate exploitation risk, data breach likely | SQLi, RCE, auth bypass | | 🟠 HIGH | Serious vulnerability, exploit path exists | XSS, IDOR, hardcoded secrets | | 🟡 MEDIUM | Exploitable with conditions or chaining | CSRF, open redirect, weak crypto | | 🔵 LOW | Best practice violation, low direct risk | Verbose errors, missing headers | | ⚪ INFO | Observation worth noting, not a vulnerability | Outdated dependency (no CVE) |

Output Rules

• Always produce a findings summary table first (counts by severity)
• Never auto-apply any patch — present patches for human review only
• Always include a confidence rating per finding (High / Medium / Low)
• Group findings by category, not by file
• Be specific — include file path, line number, and the exact vulnerable code snippet
• Explain the risk in plain English — what could an attacker do with this?
• If the codebase is clean, say so clearly: "No vulnerabilities found" with what was scanned

Reference Files

For detailed detection guidance, load the following reference files as needed:

• references/vuln-categories.md — Deep reference for every vulnerability category with detection signals, safe patterns, and escalation checkers
  • Search patterns: SQL injection, XSS, command injection, SSRF, BOLA, IDOR, JWT, CSRF, secrets, cryptography, race condition, path traversal
• references/secret-patterns.md — Regex patterns, entropy-based detection, and CI/CD secret risks
  • Search patterns: API key, token, private key, connection string, entropy, .env, GitHub Actions, Docker, Terraform
• references/language-patterns.md — Framework-specific vulnerability patterns for JavaScript, Python, Java, PHP, Go, Ruby, and Rust
  • Search patterns: Express, React, Next.js, Django, Flask, FastAPI, Spring Boot, PHP, Go, Rails, Rust
• references/vulnerable-packages.md — Curated CVE watchlist for npm, pip, Maven, Rubygems, Cargo, and Go modules
  • Search patterns: lodash, axios, jsonwebtoken, Pillow, log4j, nokogiri, CVE
• references/report-format.md — Structured output template for security reports with finding cards, dependency audit, secrets scan, and patch proposal formatting
  • Search patterns: report, format, template, finding, patch, summary, confidence