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.
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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.
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</> SKILL.md
insecure-defaults.SKILL.md
---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
## When to Use
- **Security audits** of production applications (auth, crypto, API security)
- **Configuration review** of deployment files, IaC templates, Docker configs
- **Code review** of environment variable handling and secrets management
- **Pre-deployment checks** for hardcoded credentials or weak defaults
## When NOT to Use
Do not use this skill for:
- **Test fixtures** explicitly scoped to test environments (files in `test/`, `spec/`, `__tests__/`)
- **Example/template files** (`.example`, `.template`, `.sample` suffixes)
- **Development-only tools** (local Docker Compose for dev, debug scripts)
- **Documentation examples** in README.md or docs/ directories
- **Build-time configuration** that gets replaced during deployment
- **Crash-on-missing behavior** where app won't start without proper config (fail-secure)
When in doubt: trace the code path to determine if the app runs with the default or crashes.
## Rationalizations to Reject
- **"It's just a development default"** → If it reaches production code, it's a finding
- **"The production config overrides it"** → Verify prod config exists; code-level vulnerability remains if not
- **"This would never run without proper config"** → Prove it with code trace; many apps fail silently
- **"It's behind authentication"** → Defense in depth; compromised session still exploits weak defaults
- **"We'll fix it before release"** → Document now; "later" rarely comes
## Workflow
Follow this workflow for every potential finding:
### 1. SEARCH: Perform Project Discovery and Find Insecure Defaults
Determine language, framework, and project conventions. Use this information to further discover things like secret storage locations, secret usage patterns, credentialed third-party integrations, cryptography, and any other relevant configuration. Further use information to analyze insecure default configurations.
**Example**
Search for patterns in `**/config/`, `**/auth/`, `**/database/`, and env files:
- **Fallback secrets:** `getenv.*\) or ['"]`, `process\.env\.[A-Z_]+ \|\| ['"]`, `ENV\.fetch.*default:`
