# Use of Hard-coded, Security-relevant Constants (CWE-547)

The product uses hard-coded constants instead of symbolic names for security-critical values, which increases the likelihood of mistakes during code maintenance or security reviews.

**Stack:** JavaScript

- Prevalence: Focused 2 languages covered
- Impact: Medium Review recommended
- Prevention: Documented 2 fix examples

**OWASP:** Security Misconfiguration (A05:2021-Security Misconfiguration) - #5

## Description

Hard-coded values make code harder to understand and maintain. When security-relevant values are hard-coded, it increases the risk of errors when the code needs to be modified.

## Prevention

Prevention strategies for Hardcoded Security Constants based on 1 Shoulder detection rules.

### Key Practices

- Use environment variables

### JavaScript

Use environment variables for URLs with localhost as a development fallback

## Warning Signs

- [LOW] Hardcoded development URL found: ...
Development URLs like localhost should be configured via environment variables.

- [LOW] hardcoded development URLs (localhost, 127

## Consequences

- Modify Application Data
- Read Application Data

## Mitigations

- Use named constants or configuration for security-relevant values
- Document the meaning and purpose of all security constants
- Centralize security configuration

## Detection

- Total rules: 2
- Languages: javascript, typescript, python

## Rules by Language

### Javascript (1 rules)

- **Hardcoded Development URLs** [LOW]: Detects hardcoded development URLs (localhost, 127.0.0.1) in production code that should use environment variables.
  - Remediation: Replace hardcoded URLs with environment variables:

Before: const API_URL = 'http://localhost:3000';
After:  const API_URL = process.env.API_URL || 'http://localhost:3000';

For database connections:
Before: host: 'localhost'
After:  host: process.env.DB_HOST || 'localhost'

### Typescript (1 rules)

- **Hardcoded Development URLs** [LOW]: Detects hardcoded development URLs (localhost, 127.0.0.1) in production code that should use environment variables.
  - Remediation: Replace hardcoded URLs with environment variables:

Before: const API_URL = 'http://localhost:3000';
After:  const API_URL = process.env.API_URL || 'http://localhost:3000';

For database connections:
Before: host: 'localhost'
After:  host: process.env.DB_HOST || 'localhost'