| name | insecure-defaults |
| description | Detects fail-open insecure defaults (hardcoded secrets, weak auth, permissive security) that allow apps to run insecurely in production. Use when auditing security, reviewing config management, or analyzing environment variable handling. |
| allowed-tools | ["Read","Grep","Glob","Bash"] |
Insecure Defaults Detection
Finds fail-open vulnerabilities where apps run insecurely with missing configuration. Distinguishes exploitable defaults from fail-secure patterns that crash safely.
- Fail-open (CRITICAL):
SECRET = env.get('KEY') or 'default' → App runs with weak secret
- Fail-secure (SAFE):
SECRET = env['KEY'] → App crashes if missing
Scope
Audit production-reachable code for auth, crypto, API security, deployment configs, secrets management, and environment variable handling.
Skip test fixtures (test/, spec/, __tests__/), example/template files, dev-only tools, documentation examples, build-time config replaced during deploy, and fail-secure patterns (crash-on-missing).
When in doubt: trace the code path — does the app run with the default, or crash?
Common Rationalizations (reject these)
- "Just a dev default" → if it reaches production code, it's a finding
- "Prod config overrides it" → verify prod config exists; code-level vulnerability remains otherwise
- "Would never run without config" → prove it with code trace; many apps fail silently
- "It's behind auth" → defense in depth; compromised session still exploits weak defaults
- "We'll fix before release" → document now; "later" rarely comes
Workflow
1. Search: discover and scan
Determine language, framework, and project conventions. Identify secret storage, usage patterns, third-party integrations, and crypto config.
Search **/config/, **/auth/, **/database/, and env files for:
- Fallback secrets:
getenv.*\) or ['"], process\.env\.[A-Z_]+ \|\| ['"], ENV\.fetch.*default:
- Hardcoded credentials:
password.*=.*['"][^'"]{8,}['"], api[_-]?key.*=.*['"][^'"]+['"]
- Weak defaults:
DEBUG.*=.*true, AUTH.*=.*false, CORS.*=.*\*
- Crypto algorithms:
MD5|SHA1|DES|RC4|ECB in security contexts
Tailor search to discovery results. Focus on production-reachable code.
2. Verify: trace actual behavior
For each match, trace the code path:
- When is this executed? (startup vs. runtime)
- What happens if the config variable is missing?
- Is there validation enforcing secure config?
3. Confirm: production impact
- Config provided in prod → lower severity (still a code-level vulnerability)
- Config missing or uses default → critical
4. Report: with evidence
Finding: Hardcoded JWT Secret Fallback
Location: src/auth/jwt.ts:15
Pattern: const secret = process.env.JWT_SECRET || 'default';
Verification: App starts without JWT_SECRET; secret used in jwt.sign() at line 42
Production Impact: Dockerfile missing JWT_SECRET
Exploitation: Attacker forges JWTs using 'default', gains unauthorized access
Quick Verification Checklist
Fallback Secrets: SECRET = env.get(X) or Y
→ Verify: App starts without env var? Secret used in crypto/auth?
→ Skip: Test fixtures, example files
Default Credentials: Hardcoded username/password pairs
→ Verify: Active in deployed config? No runtime override?
→ Skip: Disabled accounts, documentation examples
Fail-Open Security: AUTH_REQUIRED = env.get(X, 'false')
→ Verify: Default is insecure (false/disabled/permissive)?
→ Safe: App crashes or default is secure (true/enabled/restricted)
Weak Crypto: MD5/SHA1/DES/RC4/ECB in security contexts
→ Verify: Used for passwords, encryption, or tokens?
→ Skip: Checksums, non-security hashing
Permissive Access: CORS *, permissions 0777, public-by-default
→ Verify: Default allows unauthorized access?
→ Skip: Explicitly configured permissiveness with justification
Debug Features: Stack traces, introspection, verbose errors
→ Verify: Enabled by default? Exposed in responses?
→ Skip: Logging-only, not user-facing
For detailed examples and counter-examples, see examples.md.
