# Generation of Error Message Containing Sensitive Information (CWE-209)

The product generates an error message that includes sensitive information about its environment, users, or associated data.

**Stack:** Python

- Prevalence: 中 覆盖 3 种语言
- Impact: 中 建议审查
- Prevention: 已记录 5 个修复示例

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

## Description

The sensitive information may be valuable information on its own, or it may be useful for launching other, more serious attacks. The error message may be created in different ways, and the information that is included can range widely.

## Prevention

基于 2 条 Shoulder 检测规则的 Error Message Information Leak 预防策略。

### Python

Log full exception details internally but return generic error messages to users

Return generic responses; log internal paths server-side only

## Warning Signs

- [MEDIUM] error messages that expose sensitive implementation details like
stack traces, database errors, file
- [MEDIUM] responses that include internal file paths, IP addresses, or system
information

## Consequences

- 读取应用程序数据
- 读取文件或目录

## Mitigations

- 在内部处理异常,不向用户显示错误
- 为 404、500 等 HTTP 错误创建默认错误页
- 实现适当的错误处理,在服务器端记录详细错误,而向用户显示通用消息

## Detection

- Total rules: 5
- Languages: go, javascript, typescript, python

## Rules by Language

### Python (2 rules)

- **Error Message Information Disclosure** [MEDIUM]: Detects error messages that expose sensitive implementation details like
stack traces, database errors, file paths, or internal system information.
This information can help attackers understand the system architecture.
  - Remediation: Log full exception details internally but return generic error messages to users.

```python
import logging
from flask import jsonify

logger = logging.getLogger(__name__)

@app.route('/api/data')
def get_data():
    try:
        return jsonify(process_data())
    except Exception as e:
        logger.error(f"Processing failed: {e}", exc_info=True)
        return jsonify({'error': 'Internal server error'}), 500
```

Learn more: https://shoulder.dev/learn/python/cwe-209/error-message-exposure
- **Internal Path and IP Address Disclosure** [MEDIUM]: Detects responses that include internal file paths, IP addresses, or system
information. This information helps attackers understand the system architecture,
file structure, and internal network topology.
  - Remediation: Return generic error messages; log internal details without exposing them in responses.

```python
import logging
from flask import jsonify

logger = logging.getLogger(__name__)

@app.route('/info')
def get_info():
    logger.info(f"Request to {__file__}")  # Log internally
    return jsonify({'status': 'ok', 'version': '1.0'})  # Generic response
```

Learn more: https://shoulder.dev/learn/python/cwe-209/internal-path-disclosure