# Improper Handling of Exceptional Conditions (CWE-755)

The product does not handle or incorrectly handles an exceptional condition.

**Stack:** JavaScript

- Prevalence: Moyenne 3 langages couverts
- Impact: Élevé 1 règles de sévérité élevée
- Prevention: Documentée 4 exemples de correctifs

**OWASP:** Insecure Design (A04:2021-Insecure Design) - #4

## Description

When exceptional conditions are not properly handled, the product may enter an undefined state, crash, or expose sensitive information. This can lead to denial of service, information disclosure, or unexpected behavior.

## Prevention

Stratégies de prévention pour Improper Handling of Exceptional Conditions basées sur 1 règles de détection Shoulder.

### JavaScript

Use finally blocks to release resources (connections, file handles) on all code paths

## Warning Signs

- [MEDIUM] Resource at ... may not be released when exceptions occur
- [MEDIUM] code that allocates resources (files, connections, memory) within
try blocks but fails to release th

## Consequences

- DoS
- Lecture des données de l'application
- Exécuter du code non autorisé

## Mitigations

- Anticipez toutes les conditions exceptionnelles potentielles et gérez-les correctement
- Utilisez des blocs try-catch et des mécanismes appropriés de gestion d'erreurs
- Échouez de manière sécurisée lorsqu'une exception se produit

## Detection

- Total rules: 4
- Languages: go, javascript, typescript, python

## Rules by Language

### Javascript (1 rules)

- **Resource Exhaustion via Exception Handling** [MEDIUM]: Detects code that allocates resources (files, connections, memory) within
try blocks but fails to release them in finally blocks or error paths.

When exceptions occur, resources may not be properly cleaned up, leading
to resource exhaustion, memory leaks, and denial of service.
  - Remediation: Use finally blocks or try-with-resources pattern:

```javascript
// ✅ SAFE - Cleanup in finally
let connection;
try {
  connection = await db.getConnection();
  await connection.query(sql);
} catch (error) {
  logger.error('Query failed:', error);
  throw error;
} finally {
  if (connection) {
    await connection.release();
  }
}
```

### Typescript (1 rules)

- **Resource Exhaustion via Exception Handling** [MEDIUM]: Detects code that allocates resources (files, connections, memory) within
try blocks but fails to release them in finally blocks or error paths.

When exceptions occur, resources may not be properly cleaned up, leading
to resource exhaustion, memory leaks, and denial of service.
  - Remediation: Use finally blocks or try-with-resources pattern:

```javascript
// ✅ SAFE - Cleanup in finally
let connection;
try {
  connection = await db.getConnection();
  await connection.query(sql);
} catch (error) {
  logger.error('Query failed:', error);
  throw error;
} finally {
  if (connection) {
    await connection.release();
  }
}
```