# Improper Restriction of XML External Entity Reference (CWE-611)

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.

**Stack:** JavaScript

- Prevalence: Media 3 lenguajes cubiertos
- Impact: Alto 3 reglas de severidad alta
- Prevention: Documentada 3 ejemplos de corrección

**OWASP:** Security Misconfiguration (A05:2021-Security Misconfiguration) - #5

## Description

XML External Entity (XXE) attacks exploit features of XML parsers to read local files, perform server-side request forgery, or cause denial of service.

## Prevention

Estrategias de prevención para XML External Entity (XXE) basadas en 1 reglas de detección de Shoulder.

### JavaScript

Disable external entity processing in XML parsers or use JSON instead of XML

## Warning Signs

- [HIGH] unsafe XML parsing that could allow XML External Entity (XXE) attacks

## Consequences

- Leer datos de la aplicación
- Leer archivos o directorios
- DoS

## Mitigations

- Desactiva el procesamiento de entidades externas en los parsers XML
- Usa formatos de datos menos complejos como JSON cuando sea posible
- Valida y sanea las entradas XML

## Detection

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

## Rules by Language

### Javascript (1 rules)

- **XML External Entity (XXE) Injection** [HIGH]: Detects unsafe XML parsing that could allow XML External Entity (XXE) attacks.
XXE can lead to file disclosure, SSRF, denial of service, and other attacks.
  - Remediation: Disable external entity processing or use JSON instead of XML.

```javascript
const { XMLParser } = require('fast-xml-parser');
const parser = new XMLParser({ processEntities: false });
const result = parser.parse(xmlData);
```

Learn more: https://shoulder.dev/learn/javascript/cwe-611/xxe

### Typescript (1 rules)

- **XML External Entity (XXE) Injection** [HIGH]: Detects unsafe XML parsing that could allow XML External Entity (XXE) attacks.
XXE can lead to file disclosure, SSRF, denial of service, and other attacks.
  - Remediation: Disable external entity processing or use JSON instead of XML.

```javascript
const { XMLParser } = require('fast-xml-parser');
const parser = new XMLParser({ processEntities: false });
const result = parser.parse(xmlData);
```

Learn more: https://shoulder.dev/learn/javascript/cwe-611/xxe