references/vuln-categories.md
# Vulnerability Categories — Deep Reference
This file contains detailed detection guidance for every vulnerability category.
Load this during Step 4 of the scan workflow.
---
## 1. Injection Flaws
### SQL Injection
**What to look for:**
- String concatenation or interpolation inside SQL queries
- Raw `.query()`, `.execute()`, `.raw()` calls with variables
- ORM `whereRaw()`, `selectRaw()`, `orderByRaw()` with user input
- Second-order SQLi: data stored safely, then used unsafely later
- Stored procedures called with unsanitized input
**Detection signals (all languages):**
```
"SELECT ... " + variable
`SELECT ... ${variable}`
f"SELECT ... {variable}"
"SELECT ... %s" % variable # Only safe with proper driver parameterization
cursor.execute("... " + input)
db.raw(`... ${req.params.id}`)
```
**Safe patterns (parameterized):**
```js
db.query('SELECT * FROM users WHERE id = ?', [userId])
User.findOne({ where: { id: userId } }) // ORM safe
```
**Escalation checkers:**
- Is the query result ever used in another query? (second-order)
- Is the table/column name user-controlled? (cannot be parameterized — must allowlist)
---
### Cross-Site Scripting (XSS)
**What to look for:**
- `innerHTML`, `outerHTML`, `document.write()` with user data
- `dangerouslySetInnerHTML` in React
- Template engines rendering unescaped: `{{{ var }}}` (Handlebars), `!= var` (Pug)
- jQuery `.html()`, `.append()` with user data
- `eval()`, `setTimeout(string)`, `setInterval(string)` with user data
- DOM-based: `location.hash`, `document.referrer`, `window.name` written to DOM
- Stored XSS: user input saved to DB, rendered without escaping later
**Detection by framework:**
- **React**: Safe by default EXCEPT `dangerouslySetInnerHTML`
- **Angular**: Safe by default EXCEPT `bypassSecurityTrustHtml`
- **Vue**: Safe by default EXCEPT `v-html`
- **Vanilla JS**: Every DOM write is suspect
---
### Command Injection
**What to look for (Node.js):**
```js
exec(userInput)
execSync(`ping ${host}`)
spawn('sh', ['-c', userInput])
child_process.exec('ls ' + dir)
```
**What to look for (Python):**
```python
os.system(user_input)
subprocess.call(user_input, shell=True)
eval(user_input)
```
**What to look for (PHP):**
```php
exec($input)
system($_GET['cmd'])
passthru($input)
`$input` # backtick operator
```
**Safe alternatives:** Use array form of spawn/subprocess without shell=True; use allowlists for commands.
---
### Server-Side Request Forgery (SSRF)
**What to look for:**
- HTTP requests where the URL is user-controlled
- Webhooks, URL preview, image fetch features
- PDF generators that fetch external URLs
- Redirects to user-supplied URLs
**High-risk targets:**
- AWS metadata service: `169.254.169.254`
- Internal services: `localhost`, `127.0.0.1`, `10.x.x.x`, `192.168.x.x`
- Cloud metadata endpoints
**Detection:**
```js
fetch(req.body.url)
axios.get(userSuppliedUrl)
http.get(params.webhook)
```
---
## 2. Authentication & Access Control
### Broken Object Level Authorization (BOLA / IDOR)
**What to look for:**
- Resource IDs taken directly from URL/params without ownership check
- `findById(req.params.id)` without verifying `userId === currentUser.id`
- Numeric sequential IDs (easily guessable)
**Example vulnerable pattern:**
```js
// VULNERABLE: no ownership check
app.get('/api/documents/:id', async (req, res) => {
const doc = await Document.findById(req.params.id);
res.json(doc);
});
// SAFE: verify ownership
app.get('/api/documents/:id', async (req, res) => {
const doc = await Document.findOne({ _id: req.params.id, owner: req.user.id });
if (!doc) return res.status(403).json({ error: 'Forbidden' });
res.json(doc);
});
```
---
### JWT Vulnerabilities
**What to look for:**
- `alg: "none"` accepted
- Weak or hardcoded secrets: `secret`, `password`, `1234`
- No expiry (`exp` claim) validation
- Algorithm confusion (RS256 → HS256 downgrade)
- JWT stored in `localStorage` (XSS risk; prefer httpOnly cookie)
**Detection:**
```js
jwt.verify(token, secret, { algorithms: ['HS256'] }) // Check algorithms array
jwt.decode(token) // WARNING: decode does NOT verify signature
```
---
### Missing Authentication / Authorization
**What to look for:**
- Admin or sensitive endpoints missing auth middleware
- Routes defined after `app.use(authMiddleware)` vs before it
- Feature flags or debug endpoints left exposed in production
- GraphQL resolvers missing auth checks at field level
---
### CSRF
**What to look for:**
- State-changing operations (POST/PUT/DELETE) without CSRF token
- APIs relying only on cookies for auth without SameSite attribute
- Missing `SameSite=Strict` or `SameSite=Lax` on session cookies
---
## 3. Secrets & Sensitive Data Exposure
### In-Code Secrets
Look for patterns like:
```
API_KEY = "sk-..."
password = "hunter2"
SECRET = "abc123"
private_key = "-----BEGIN RSA PRIVATE KEY-----"
aws_secret_access_key = "wJalrXUtn..."
```
Entropy heuristic: strings > 20 chars with high character variety in assignment context
are likely secrets even if the variable name doesn't say so.
### In Logs / Error Messages
```js
console.log('User password:', password)
logger.info({ user, token }) // token shouldn't be logged
res.status(500).json({ error: err.stack }) // stack traces expose internals
```
### Sensitive Data in API Responses
- Returning full user object including `password_hash`, `ssn`, `credit_card`
- Including internal IDs or system paths in error responses
---
## 4. Cryptography
### Weak Algorithms
| Algorithm | Issue | Replace With |
|-----------|-------|--------------|
| MD5 | Broken for security | SHA-256 or bcrypt (passwords) |
| SHA-1 | Collision attacks | SHA-256 |
| DES / 3DES | Weak key size | AES-256-GCM |
| RC4 | Broken | AES-GCM |
| ECB mode | No IV, patterns visible | GCM or CBC with random IV |
### Weak Randomness
```js
// VULNERABLE
Math.random() // not cryptographically secure
Date.now() // predictable
Math.random().toString(36) // weak token generation
// SAFE
crypto.randomBytes(32) // Node.js
secrets.token_urlsafe(32) // Python
```
### Password Hashing
```python
# VULNERABLE
hashlib.md5(password.encode()).hexdigest()
hashlib.sha256(password.encode()).hexdigest()
# SAFE
bcrypt.hashpw(password, bcrypt.gensalt(rounds=12))
argon2.hash(password)
```
---
## 5. Insecure Dependencies
### What to flag:
- Packages with known CVEs in installed version range
- Packages abandoned > 2 years with no security updates
- Packages with extremely broad permissions for their stated purpose
- Transitive dependencies pulling in known-bad packages
- Pinned versions that are significantly behind current (possible unpatched vulns)
### High-risk package watchlist: see `references/vulnerable-packages.md`
---
## 6. Business Logic
### Race Conditions (TOCTOU)
```js
// VULNERABLE: check then act without atomic lock
const balance = await getBalance(userId);
if (balance >= amount) {
await deductBalance(userId, amount); // race condition between check and deduct
}
// SAFE: use atomic DB transaction or optimistic locking
await db.transaction(async (trx) => {
const user = await User.query(trx).forUpdate().findById(userId);
if (user.balance < amount) throw new Error('Insufficient funds');
await user.$query(trx).patch({ balance: user.balance - amount });
});
```
### Missing Rate Limiting
Flag endpoints that:
- Accept authentication credentials (login, 2FA)
- Send emails or SMS
- Perform expensive operations
- Expose user enumeration (password reset, registration)
---
## 7. Path Traversal
```python
# VULNERABLE
filename = request.args.get('file')
with open(f'/var/uploads/{filename}') as f: # ../../../../etc/passwd
# SAFE
filename = os.path.basename(request.args.get('file'))
safe_path = os.path.join('/var/uploads', filename)
if not safe_path.startswith('/var/uploads/'):
abort(400)
```
SKILL.md
---
name: security-review
description: 'AI-powered codebase security scanner that reasons about code like a security researcher — tracing data flows, understanding component interactions, and catching vulnerabilities that pattern-matching tools miss. Use this skill when asked to scan code for security vulnerabilities, find bugs, check for SQL injection, XSS, command injection, exposed API keys, hardcoded secrets, insecure dependencies, access control issues, or any request like "is my code secure?", "review for security issues", "audit this codebase", or "check for vulnerabilities". Covers injection flaws, authentication and access control bugs, secrets exposure, weak cryptography, insecure dependencies, and business logic issues across JavaScript, TypeScript, Python, Java, PHP, Go, Ruby, and Rust.'
---
# 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`