CWE-212 Base Incompleto

Improper Removal of Sensitive Information Before Storage or Transfer

This vulnerability occurs when an application stores or transmits a resource containing sensitive data without properly cleaning it first, potentially exposing that information to unauthorized…

Definición

What is CWE-212?

This vulnerability occurs when an application stores or transmits a resource containing sensitive data without properly cleaning it first, potentially exposing that information to unauthorized parties.
Many resources like documents, database entries, or network packets contain sensitive information—such as internal comments, file paths, or IP addresses—that is only relevant to a specific user or a trusted group. Before sharing that resource more broadly (e.g., exporting a document or forwarding a network request), this private data must be systematically removed, a process often called data cleansing or scrubbing. For developers, this means actively identifying and stripping sensitive metadata or embedded content. Common oversights include leaving reviewer comments in a final document draft or failing to remove internal server headers from outgoing HTTP requests. Without these checks, seemingly innocuous data sharing can inadvertently leak confidential details.
Impacto en el mundo real

Real-world CVEs caused by CWE-212

  • CVE-2019-3733

    Cryptography library does not clear heap memory before release

  • CVE-2005-0406

    Some image editors modify a JPEG image, but the original EXIF thumbnail image is left intact within the JPEG. (Also an interaction error).

  • CVE-2002-0704

    NAT feature in firewall leaks internal IP addresses in ICMP error messages.

Cómo lo explotan los atacantes

Ruta del atacante paso a paso

  1. 1

    Identifica una ruta de código que maneje entrada no confiable sin validación.

  2. 2

    Crea un payload que ejercite el comportamiento inseguro — inyección, traversal, overflow o abuso de lógica.

  3. 3

    Envía el payload a través de una solicitud normal y observa la reacción de la aplicación.

  4. 4

    Itera hasta que la respuesta filtre datos, ejecute código del atacante o escale privilegios.

Ejemplo de código vulnerable

Vulnerable PHP

This code either generates a public HTML user information page or a JSON response containing the same user information.

Vulnerable PHP 
```
// API flag, output JSON if set* 
  $json = $_GET['json']
  $username = $_GET['user']
  if(!$json)
  {
  ```
  		$record = getUserRecord($username);
  		foreach($record as $fieldName => $fieldValue)
  		{
  				if($fieldName == "email_address") {
```
// skip displaying user emails* 
  						continue;}
  				else{
  				```
  					writeToHtmlPage($fieldName,$fieldValue);
  				}
  		}
  }
  else
  {
  	$record = getUserRecord($username);
  	echo json_encode($record);
  }
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-212

  • Requirements Clearly specify which information should be regarded as private or sensitive, and require that the product offers functionality that allows the user to cleanse the sensitive information from the resource before it is published or exported to other parties.
  • Architecture and Design Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
  • Implementation Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.
  • Implementation Avoid errors related to improper resource shutdown or release (CWE-404), which may leave the sensitive data within the resource if it is in an incomplete state.
Señales de detección

How to detect CWE-212

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-212 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.

Solicitar demo Probar Plexicus gratis
Preguntas frecuentes

Frequently asked questions

¿Qué es CWE-212?

This vulnerability occurs when an application stores or transmits a resource containing sensitive data without properly cleaning it first, potentially exposing that information to unauthorized parties.

¿Qué gravedad tiene CWE-212?

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-212?

MITRE no ha especificado plataformas afectadas para esta CWE — puede aplicar a la mayoría de los stacks de aplicaciones.

¿Cómo puedo prevenir CWE-212?

Clearly specify which information should be regarded as private or sensitive, and require that the product offers functionality that allows the user to cleanse the sensitive information from the resource before it is published or exported to other parties. Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe…

¿Cómo detecta y corrige Plexicus CWE-212?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-212 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-212?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/212.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

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Recursos

Further reading

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