Node.js Security Audit
Structured security audit for Node.js HTTP servers and web applications.
Audit Checklist
Critical (Must Fix Before Deploy)
Hardcoded Secrets
- Search for: API keys, passwords, tokens in source code
- Pattern:
grep -rn "password\|secret\|token\|apikey\|api_key" --include="*.js" --include="*.ts" | grep -v node_modules | grep -v "process.env\|\.env"
- Fix: Move to env vars, fail if missing:
if (!process.env.SECRET) process.exit(1);
XSS in Dynamic Content
- Search for:
innerHTML, template literals injected into DOM, unsanitized user input in responses
- Fix: Use
textContent, or escape: str.replace(/[&<>"']/g, c => ({'&':'&','<':'<','>':'>','"':'"',"'":"'"}[c]))
SQL/NoSQL Injection
- Search for: String concatenation in queries,
eval(), Function() with user input
- Fix: Parameterized queries, input validation
High (Should Fix)
CORS Misconfiguration
- Search for:
Access-Control-Allow-Origin: *
- Fix: Allowlist specific origins:
const origin = ALLOWED.has(req.headers.origin) ? req.headers.origin : ALLOWED.values().next().value
Auth Bypass
- Check: Every route that should require auth actually checks it
- Common miss: Static file routes, agent/webhook endpoints, health checks that expose data
Path Traversal
- Check:
path.normalize() + startsWith(allowedDir) on all file-serving routes
- Extra: Resolve symlinks with
fs.realpathSync() and re-check
Medium (Recommended)
Security Headers
const HEADERS = {
'X-Frame-Options': 'SAMEORIGIN',
'X-Content-Type-Options': 'nosniff',
'Referrer-Policy': 'strict-origin-when-cross-origin',
'Permissions-Policy': 'camera=(), microphone=(), geolocation=()',
};
// Apply to all responses
Rate Limiting
const attempts = new Map(); // ip -> { count, resetAt }
const LIMIT = 5, WINDOW = 60000;
function isLimited(ip) {
const now = Date.now(), e = attempts.get(ip);
if (!e || now > e.resetAt) { attempts.set(ip, {count:1, resetAt:now+WINDOW}); return false; }
return ++e.count > LIMIT;
}
Input Validation
- Body size limits:
if (bodySize > 1048576) { req.destroy(); return; }
- JSON parse in try/catch
- Type checking on expected fields
Low (Consider)
Dependency Audit: npm audit
Error Leakage: Don't send stack traces to clients in production
Cookie Security: HttpOnly; Secure; SameSite=Strict
Report Format
## Security Audit: [filename]
### Critical
1. **[Category]** Description — File:Line — Fix: ...
### High
...
### Medium
...
### Low
...
### Summary
X critical, X high, X medium, X low
1---2name: nodejs-security-audit3description: Audit Node.js HTTP servers and web apps for security vulnerabilities. Checks OWASP Top 10, CORS, auth bypass, XSS, path traversal, hardcoded secrets, missing headers, rate limiting, and input validation. Use when reviewing server code before deployment or after changes.4---56# Node.js Security Audit78Structured security audit for Node.js HTTP servers and web applications.910## Audit Checklist1112### Critical (Must Fix Before Deploy)1314**Hardcoded Secrets**15- Search for: API keys, passwords, tokens in source code16- Pattern: `grep -rn "password\|secret\|token\|apikey\|api_key" --include="*.js" --include="*.ts" | grep -v node_modules | grep -v "process.env\|\.env"`17- Fix: Move to env vars, fail if missing: `if (!process.env.SECRET) process.exit(1);`1819**XSS in Dynamic Content**20- Search for: `innerHTML`, template literals injected into DOM, unsanitized user input in responses21- Fix: Use `textContent`, or escape: `str.replace(/[&<>"']/g, c => ({'&':'&','<':'<','>':'>','"':'"',"'":"'"}[c]))`2223**SQL/NoSQL Injection**24- Search for: String concatenation in queries, `eval()`, `Function()` with user input25- Fix: Parameterized queries, input validation2627### High (Should Fix)2829**CORS Misconfiguration**30- Search for: `Access-Control-Allow-Origin: *`31- Fix: Allowlist specific origins: `const origin = ALLOWED.has(req.headers.origin) ? req.headers.origin : ALLOWED.values().next().value`3233**Auth Bypass**34- Check: Every route that should require auth actually checks it35- Common miss: Static file routes, agent/webhook endpoints, health checks that expose data3637**Path Traversal**38- Check: `path.normalize()` + `startsWith(allowedDir)` on all file-serving routes39- Extra: Resolve symlinks with `fs.realpathSync()` and re-check4041### Medium (Recommended)4243**Security Headers**44```javascript45const HEADERS = {46 'X-Frame-Options': 'SAMEORIGIN',47 'X-Content-Type-Options': 'nosniff',48 'Referrer-Policy': 'strict-origin-when-cross-origin',49 'Permissions-Policy': 'camera=(), microphone=(), geolocation=()',50};51// Apply to all responses52```5354**Rate Limiting**55```javascript56const attempts = new Map(); // ip -> { count, resetAt }57const LIMIT = 5, WINDOW = 60000;58function isLimited(ip) {59 const now = Date.now(), e = attempts.get(ip);60 if (!e || now > e.resetAt) { attempts.set(ip, {count:1, resetAt:now+WINDOW}); return false; }61 return ++e.count > LIMIT;62}63```6465**Input Validation**66- Body size limits: `if (bodySize > 1048576) { req.destroy(); return; }`67- JSON parse in try/catch68- Type checking on expected fields6970### Low (Consider)7172**Dependency Audit:** `npm audit`73**Error Leakage:** Don't send stack traces to clients in production74**Cookie Security:** `HttpOnly; Secure; SameSite=Strict`7576## Report Format7778```79## Security Audit: [filename]8081### Critical821. **[Category]** Description — File:Line — Fix: ...8384### High85...8687### Medium88...8990### Low91...9293### Summary94X critical, X high, X medium, X low95```
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