# Missing Authentication for Critical Function (CWE-306)

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

**Stack:** JavaScript

- Prevalence: High Frequently exploited
- Impact: High 6 high-severity rules
- Prevention: Documented 6 fix examples

**OWASP:** Identification and Authentication Failures (A07:2021-Identification and Authentication Failures) - #7

## Description

As data traverses trust boundaries, the data should be validated before being processed. When authentication is not applied to critical functions, attackers can invoke these functions without proving their identity.

## Prevention

### JavaScript

Add @UseGuards decorator with authentication guard at controller or method level

## Warning Signs

- [HIGH] NestJS endpoint has no @UseGuards() decorator for authentication

## Consequences

- Gain Privileges
- Read Application Data
- Modify Application Data
- Execute Unauthorized Code

## Mitigations

- Divide the software into components with different trust levels
- Identify all areas with security-critical functionality and require authentication for all such areas
- Ensure that appropriate access controls are enforced

## Detection

- Total rules: 6
- Languages: python, go, typescript

## Rules by Language

### Typescript (1 rules)

- **NestJS Endpoint Missing Authentication Guard** [HIGH]: Endpoints without @UseGuards or @Public decorators are accessible to
unauthenticated users, enabling unauthorized access.
  - Remediation: Add @UseGuards decorator at controller or method level.

```typescript
import { UseGuards } from '@nestjs/common';
import { JwtAuthGuard } from '../auth/jwt-auth.guard';

@Controller('users')
@UseGuards(JwtAuthGuard)
export class UsersController {
  @Get(':id')
  findOne(@Param('id') id: string) {
    return this.usersService.findOne(id);
  }
}
```

Learn more: https://shoulder.dev/learn/typescript/cwe-306/missing-auth-guard