# Declaration of Catch for Generic Exception (CWE-396)

Catching overly broad exceptions defeats the purpose of typed exceptions and can result in unexpected behavior.

- Prevalence: 限定的 1 言語をカバー
- Impact: ミディアム レビュー推奨
- Prevention: 文書化済み 1 件の修正例

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

## Description

When exceptions are caught too broadly (e.g., catching Exception instead of specific types), the code may inadvertently catch and suppress exceptions it wasn't designed to handle, hiding bugs or security issues.

## Prevention

### Python

Catch specific exceptions instead of bare except: or except BaseException

## Warning Signs

- [LOW] overly broad exception handlers (bare except: or except BaseException)
that catch system exceptions 

## Consequences

- DoS
- 活動の隠蔽

## Mitigations

- 対処方法が分かっている具体的な例外型のみをキャッチする
- 適切に処理できない例外は再スローする
- 予期しない例外は再スローする前にログに記録する

## Detection

- Total rules: 1
- Languages: python

## Rules by Language

### Python (1 rules)

- **Overly Broad Exception Handler** [LOW]: Detects overly broad exception handlers (bare except: or except BaseException)
that catch system exceptions like KeyboardInterrupt, SystemExit, which should
not be caught in normal error handling.
  - Remediation: Catch specific exceptions or use Exception instead of bare except or BaseException.

```python
try:
    process_data()
except ValueError as e:
    logger.error(f"Invalid value: {e}")
except IOError as e:
    logger.error(f"IO error: {e}")
```

Learn more: https://shoulder.dev/learn/python/cwe-396/broad-exception