# 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: Élevée Fréquemment exploitée
- Impact: Critique 2 règles de sévérité critique
- Prevention: Documentée 2 exemples de correctifs

**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

Stratégies de prévention pour Improper Authentication basées sur 1 règles de détection Shoulder.

### 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

- Obtenir des privilèges
- Contourner le mécanisme de protection
- Lecture des données de l'application

## Mitigations

- Utilisez l'authentification multifacteur
- Utilisez une bibliothèque ou un framework éprouvé pour l'authentification
- Mettez en place des politiques de mots de passe appropriées

## 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