# 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:** Go

- Prevalence: Medium 3 languages covered
- Impact: High 1 high-severity rules
- Prevention: Documented 3 fix examples

**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

Prevention strategies for Information Exposure Through Logs based on 1 Shoulder detection rules.

### Go

Never log passwords, tokens, or PII; log presence/absence instead

## Consequences

- Read Application Data
- Gain Privileges

## Mitigations

- Never log sensitive information such as passwords or tokens
- Implement log data classification and filtering
- Mask or redact sensitive data before logging

## Detection

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

## Rules by Language

### Go (1 rules)

- **Logging Sensitive Data** [MEDIUM]: Passwords, tokens, or PII logged via log.Printf or similar functions.
  - Remediation: Never log sensitive values. Log presence/absence instead of actual values.

```go
// Log only that API key is configured, not the value
if apiKey != "" {
    log.Println("API key configured")
}
```

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