# Unchecked Error Condition (CWE-391)

The product does not properly check when a function or operation returns a value that is associated with an error condition.

**Stack:** Go

- Prevalence: 보통 3개 언어 지원
- Impact: 높음 1개의 높은 심각도 규칙
- Prevention: 문서화됨 3개의 수정 예시

**OWASP:** Insecure Design (A04:2021-Insecure Design) - #4

## Description

When error conditions are not checked, the application may continue with invalid or unexpected state, potentially leading to crashes, data corruption, or security vulnerabilities.

## Prevention

1개의 Shoulder 탐지 규칙을 기반으로 한 Unchecked Error Condition 예방 전략.

### Go

Log or return errors instead of silently swallowing them

## Consequences

- DoS
- 승인되지 않은 코드 실행
- 애플리케이션 데이터 수정

## Mitigations

- 모든 반환값과 오류 조건을 확인하세요
- 필요한 곳에서는 예외 처리를 사용하세요
- 적절한 오류 복구 메커니즘을 구현하세요

## Detection

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

## Rules by Language

### Go (1 rules)

- **Empty Error Handling** [LOW]: Error check block is empty, silently swallowing errors.
  - Remediation: Log or return errors instead of ignoring them silently.

```go
if err != nil {
    log.Printf("operation failed: %v", err)
    return err
}
```

Learn more: https://shoulder.dev/learn/go/cwe-391/empty-error-handling