# 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:** JavaScript

- 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。

### JavaScript

Return generic error messages to users and log detailed errors server-side

Configure errorFormatter to strip stack traces in production and use TRPCError with generic messages

## Warning Signs

- [MEDIUM] exposure of sensitive error information (error
- [MEDIUM] Error handling exposes implementation details. Use error formatter to sanitize errors in production.

## 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

### Javascript (2 rules)

- **Information Exposure Through Error Messages** [MEDIUM]: Detects exposure of sensitive error information (error.message, error.stack,
raw error objects) in HTTP responses. This can leak:

- Internal file paths and directory structure
- Database schema and query details
- Third-party API endpoints and credentials
- Software versions and technology stack
- Business logic and validation rules

Attackers use this information to:
- Map internal architecture
- Identify vulnerable dependencies
- Craft targeted attacks
- Bypass security controls
  - Remediation: Return generic error messages to users and log detailed errors server-side.

```javascript
} catch (error) {
  logger.error('Failed', { error: error.message });
  res.status(500).json({ error: 'An error occurred' });
}
```

Learn more: https://shoulder.dev/learn/javascript/cwe-209/error-message-exposure
- **tRPC Error Information Disclosure** [MEDIUM]: Exposing raw errors, stack traces, or database details to clients aids attackers
in reconnaissance and exploitation.
  - Remediation: Use errorFormatter to sanitize errors in production.

```typescript
export const t = initTRPC.context<Context>().create({
  errorFormatter({ shape }) {
    return {
      ...shape,
      data: {
        ...shape.data,
        stack: process.env.NODE_ENV === 'production' ? undefined : shape.data.stack
      }
    };
  }
});
```

Learn more: https://shoulder.dev/learn/typescript/cwe-209/error-information-leak

### Typescript (2 rules)

- **Information Exposure Through Error Messages** [MEDIUM]: Detects exposure of sensitive error information (error.message, error.stack,
raw error objects) in HTTP responses. This can leak:

- Internal file paths and directory structure
- Database schema and query details
- Third-party API endpoints and credentials
- Software versions and technology stack
- Business logic and validation rules

Attackers use this information to:
- Map internal architecture
- Identify vulnerable dependencies
- Craft targeted attacks
- Bypass security controls
  - Remediation: Return generic error messages to users and log detailed errors server-side.

```javascript
} catch (error) {
  logger.error('Failed', { error: error.message });
  res.status(500).json({ error: 'An error occurred' });
}
```

Learn more: https://shoulder.dev/learn/javascript/cwe-209/error-message-exposure
- **tRPC Error Information Disclosure** [MEDIUM]: Exposing raw errors, stack traces, or database details to clients aids attackers
in reconnaissance and exploitation.
  - Remediation: Use errorFormatter to sanitize errors in production.

```typescript
export const t = initTRPC.context<Context>().create({
  errorFormatter({ shape }) {
    return {
      ...shape,
      data: {
        ...shape.data,
        stack: process.env.NODE_ENV === 'production' ? undefined : shape.data.stack
      }
    };
  }
});
```

Learn more: https://shoulder.dev/learn/typescript/cwe-209/error-information-leak