# Weak Password Recovery Mechanism for Forgotten Password (CWE-640)

The product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak.

- Prevalence: High Frequently exploited
- Impact: High 3 high-severity rules
- Prevention: Documented 3 fix examples

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

## Description

Weak password recovery mechanisms can be exploited to take over user accounts. Common issues include predictable reset tokens, security questions with easily guessable answers, or lack of verification.

## Prevention

Prevention strategies for Weak Password Recovery based on 3 Shoulder detection rules.

### Go

Use crypto/rand with 32+ bytes of entropy for password reset tokens

### Node.js

Use crypto.randomBytes() instead of Math.random() for security tokens

### Python

Use the secrets module for cryptographically secure token generation

## Warning Signs

- [HIGH] predictable random number generation (Math
- [HIGH] password reset tokens generated using weak or predictable methods like timestamps or non-cryptograph

## Consequences

- Gain Privileges
- Bypass Protection Mechanism

## Mitigations

- Use strong, random tokens for password reset links
- Implement token expiration (e.g., 1 hour)
- Require additional verification like email or SMS
- Never expose the reset token in URLs that could be logged

## Detection

- Total rules: 3
- Languages: go, javascript, typescript, python

## Rules by Language

### Go (1 rules)

- **Weak Password Reset Token** [HIGH]: Password reset token uses predictable values like timestamps or math/rand.
  - Remediation: Generate reset tokens using crypto/rand with at least 32 bytes of entropy.

```go
import "crypto/rand"

func generateResetToken() (string, error) {
    b := make([]byte, 32)
    if _, err := rand.Read(b); err != nil {
        return "", err
    }
    return hex.EncodeToString(b), nil
}
```

Learn more: https://shoulder.dev/learn/go/cwe-640/weak-password-reset-token

### Javascript (1 rules)

- **Weak Password Reset Token** [HIGH]: Detects predictable random number generation (Math.random) used for password reset tokens.
  - Remediation: Use cryptographically secure random:

```javascript
const crypto = require('crypto');
const resetToken = crypto.randomBytes(32).toString('hex');
```

Learn more: https://shoulder.dev/learn/javascript/cwe-640/weak-password-reset-token

### Typescript (1 rules)

- **Weak Password Reset Token** [HIGH]: Detects predictable random number generation (Math.random) used for password reset tokens.
  - Remediation: Use cryptographically secure random:

```javascript
const crypto = require('crypto');
const resetToken = crypto.randomBytes(32).toString('hex');
```

Learn more: https://shoulder.dev/learn/javascript/cwe-640/weak-password-reset-token

### Python (1 rules)

- **Weak Password Reset Token** [HIGH]: Detects password reset tokens generated using weak or predictable methods like timestamps or non-cryptographic random.
  - Remediation: Use the secrets module for cryptographically secure token generation.

```python
import secrets
token = secrets.token_urlsafe(32)
```

Learn more: https://shoulder.dev/learn/python/cwe-640/weak-password-reset-token