# Improper Authentication (CWE-287)

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

**Stack:** Python

- Prevalence: Hoch Häufig ausgenutzt
- Impact: Kritisch 2 Regeln mit kritischem Schweregrad
- Prevention: Dokumentiert 2 Fix-Beispiele

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

## Description

Authentication is the process of determining if a claimed identity is correct. When authentication is insufficient or incorrect, attackers can assume the identity of legitimate users.

## Prevention

Präventionsstrategien für Improper Authentication basierend auf 1 Shoulder-Erkennungsregeln.

### Python

Use early returns for authentication failures and constant-time comparison

## Warning Signs

- [CRITICAL] authentication checks that can be bypassed due to missing return statements or weak boolean logic

## Consequences

- Privilegien erlangen
- Schutzmechanismus umgehen
- Anwendungsdaten lesen

## Mitigations

- Multi-Faktor-Authentifizierung verwenden
- Verwende für die Authentifizierung eine geprüfte Bibliothek oder ein Framework
- Geeignete Passwortrichtlinien umsetzen

## Detection

- Total rules: 2
- Critical: 2
- Languages: javascript, typescript, python

## Rules by Language

### Python (1 rules)

- **Authentication Bypass Vulnerability** [CRITICAL]: Detects authentication checks that can be bypassed due to missing return statements or weak boolean logic.
  - Remediation: Use early returns for authentication failures to prevent bypass.

```python
if not user or not check_password_hash(user.password_hash, password):
    return jsonify({'error': 'Invalid credentials'}), 401
```

Learn more: https://shoulder.dev/learn/python/cwe-287/authentication-bypass