CWE-211 Base Incompleto

Externally-Generated Error Message Containing Sensitive Information

This vulnerability occurs when an application triggers an error message from an external component—like a database, interpreter, or operating system—and that error reveals sensitive details about…

Definición

What is CWE-211?

This vulnerability occurs when an application triggers an error message from an external component—like a database, interpreter, or operating system—and that error reveals sensitive details about the system's internal workings, configuration, or data.
Unlike application-controlled errors, these messages originate from underlying platforms or dependencies and often include technical details developers didn't intend to expose. Attackers can deliberately trigger these errors by sending malformed inputs or causing system failures, then harvest information like stack traces, file paths, database schemas, or server versions to plan further attacks. Preventing this requires a defense-in-depth approach: configure external components to suppress verbose errors in production, implement centralized exception handling to catch and sanitize all external messages before they reach users, and ensure logging systems capture detailed diagnostics separately without exposing them through user interfaces. Regular testing with fuzzing and penetration testing helps identify what information leaks through these indirect channels.
Impacto en el mundo real

Real-world CVEs caused by CWE-211

  • chain: product does not protect against direct request of an include file, leading to resultant path disclosure when the include file does not successfully execute.

  • Single "'" inserted into SQL query leads to invalid SQL query execution, triggering full path disclosure. Possibly resultant from more general SQL injection issue.

  • chain: product does not protect against direct request of a library file, leading to resultant path disclosure when the file does not successfully execute.

  • invalid parameter triggers a failure to find an include file, leading to infoleak in error message.

  • Various invalid requests lead to information leak in verbose error messages describing the failure to instantiate a class, open a configuration file, or execute an undefined function.

  • Improper handling of filename request with trailing "/" causes multiple consequences, including information leak in Visual Basic error message.

Cómo lo explotan los atacantes

Ruta del atacante paso a paso

  1. 1

    The following servlet code does not catch runtime exceptions, meaning that if such an exception were to occur, the container may display potentially dangerous information (such as a full stack trace).

  2. 2

    In the following Java example the class InputFileRead enables an input file to be read using a FileReader object. In the constructor of this class a default input file path is set to some directory on the local file system and the method setInputFile must be called to set the name of the input file to be read in the default directory. The method readInputFile will create the FileReader object and will read the contents of the file. If the method setInputFile is not called prior to calling the method readInputFile then the File object will remain null when initializing the FileReader object. A Java RuntimeException will be raised, and an error message will be output to the user.

  3. 3

    However, the error message output to the user contains information regarding the default directory on the local file system. This information can be exploited and may lead to unauthorized access or use of the system. Any Java RuntimeExceptions that are handled should not expose sensitive information to the user.

Ejemplo de código vulnerable

Vulnerable Java

The following servlet code does not catch runtime exceptions, meaning that if such an exception were to occur, the container may display potentially dangerous information (such as a full stack trace).

Vulnerable Java
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  		String username = request.getParameter("username");
```
// May cause unchecked NullPointerException.* 
  		if (username.length() < 10) {
  		```
  			...
  		}
  }
Ejemplo de código seguro

Secure pseudo

Seguro pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
  const safe = validateAndEscape(input);
  return executeWithGuards(safe);
}
What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Lista de prevención

How to prevent CWE-211

  • System Configuration Configure the application's environment in a way that prevents errors from being generated. For example, in PHP, disable display_errors.
  • Implementation / Build and Compilation Debugging information should not make its way into a production release.
  • Implementation / Build and Compilation Debugging information should not make its way into a production release.
  • Implementation Handle exceptions internally and do not display errors containing potentially sensitive information to a user. Create default error pages if necessary.
  • Implementation The best way to prevent this weakness during implementation is to avoid any bugs that could trigger the external error message. This typically happens when the program encounters fatal errors, such as a divide-by-zero. You will not always be able to control the use of error pages, and you might not be using a language that handles exceptions.
Señales de detección

How to detect CWE-211

SAST High

Ejecuta análisis estático (SAST) sobre el código buscando el patrón inseguro en el flujo de datos.

DAST Moderate

Ejecuta pruebas dinámicas de seguridad de aplicaciones (DAST) contra el endpoint en vivo.

Runtime Moderate

Vigila los logs en tiempo de ejecución para detectar trazas de excepción inusuales, entradas malformadas o intentos de bypass de autorización.

Code review Moderate

Revisión de código: marca cualquier código nuevo que maneje entrada desde esta superficie sin usar los helpers validados del framework.

Auto-corrección de Plexicus

Plexicus detecta automáticamente CWE-211 y abre un PR de corrección en menos de 60 segundos.

Codex Remedium escanea cada commit, identifica esta debilidad concreta y entrega un pull request listo para revisión con el parche. Sin tickets. Sin traspasos.

Preguntas frecuentes

Frequently asked questions

¿Qué es CWE-211?

This vulnerability occurs when an application triggers an error message from an external component—like a database, interpreter, or operating system—and that error reveals sensitive details about the system's internal workings, configuration, or data.

¿Qué gravedad tiene CWE-211?

MITRE no ha publicado una calificación de probabilidad de explotación para esta debilidad. Trátala como de impacto medio hasta que tu modelo de amenazas demuestre lo contrario.

¿Qué lenguajes o plataformas se ven afectados por CWE-211?

MITRE lists the following affected platforms: PHP.

¿Cómo puedo prevenir CWE-211?

Configure the application's environment in a way that prevents errors from being generated. For example, in PHP, disable display_errors. Debugging information should not make its way into a production release.

¿Cómo detecta y corrige Plexicus CWE-211?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-211 en cada commit. Cuando hay coincidencia, nuestro agente Codex Remedium abre un PR de corrección con el código corregido, las pruebas y un resumen de una línea para el revisor.

¿Dónde puedo aprender más sobre CWE-211?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/211.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Listo cuando tú lo estés

Deja de pagar por desarrollador.
Empieza a cerrar el bucle.

Plexicus es el ASPM nativo de IA que escanea, filtra, corrige, pentestea y explica — de forma autónoma. Desarrolladores ilimitados, repos ilimitados, acciones de IA de uso justo. Nivel gratuito real, €269/mo anual cuando estés listo.