# Insertion of Sensitive Information into Log File (CWE-532)

Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information.

**Stack:** JavaScript

- Prevalence: Média 3 linguagens cobertas
- Impact: Alto 1 regras de severidade alta
- Prevention: Documentada 3 exemplos de correção

**OWASP:** Security Logging and Monitoring Failures (A09:2021-Security Logging and Monitoring Failures) - #9

## Description

When sensitive information like passwords, tokens, or personal data is logged, it becomes accessible to anyone with access to the logs. Log files are often stored with less security than the data they contain.

## Prevention

Estratégias de prevenção para Information Exposure Through Logs baseadas em 1 regras de detecção do Shoulder.

### JavaScript

Exclude sensitive fields from logged data using destructuring or redaction

## Warning Signs

- [MEDIUM] when user-provided sensitive data (passwords, tokens, API keys, secrets, etc

## Consequences

- Ler dados da aplicação
- Obter privilégios

## Mitigations

- Nunca registre em log informações sensíveis como senhas ou tokens
- Implemente classificação e filtragem dos dados de log
- Mascare ou redija dados sensíveis antes de registrar em log

## Detection

- Total rules: 3
- Languages: go, javascript, typescript, python

## Rules by Language

### Javascript (1 rules)

- **Sensitive Data Exposure in Logs** [MEDIUM]: Detects when user-provided sensitive data (passwords, tokens, API keys, secrets, etc.)
flows directly into logging functions without proper redaction or masking.

This rule uses taint flow analysis to detect ACTUAL sensitive data being logged,
not just variables with sensitive names. Only triggers when:
1. Data originates from user input (req.body, req.headers, etc.)
2. Contains sensitive field names (password, token, secret, etc.)
3. Flows into logging functions without sanitization

Sensitive 
  - Remediation: Exclude sensitive fields from logged data:

```javascript
const { password, ...safeBody } = req.body;
console.log('Request body:', safeBody);

function redactToken(token) {
  return token ? token.substring(0, 4) + '***' : '';
}
logger.info('Token:', redactToken(authToken));
```

Learn more: https://shoulder.dev/learn/javascript/cwe-532/sensitive-data-logging

### Typescript (1 rules)

- **Sensitive Data Exposure in Logs** [MEDIUM]: Detects when user-provided sensitive data (passwords, tokens, API keys, secrets, etc.)
flows directly into logging functions without proper redaction or masking.

This rule uses taint flow analysis to detect ACTUAL sensitive data being logged,
not just variables with sensitive names. Only triggers when:
1. Data originates from user input (req.body, req.headers, etc.)
2. Contains sensitive field names (password, token, secret, etc.)
3. Flows into logging functions without sanitization

Sensitive 
  - Remediation: Exclude sensitive fields from logged data:

```javascript
const { password, ...safeBody } = req.body;
console.log('Request body:', safeBody);

function redactToken(token) {
  return token ? token.substring(0, 4) + '***' : '';
}
logger.info('Token:', redactToken(authToken));
```

Learn more: https://shoulder.dev/learn/javascript/cwe-532/sensitive-data-logging