CWE-396 Base Borrador

Declaration of Catch for Generic Exception

This weakness occurs when code catches a generic exception type like 'Exception' or 'Throwable', which can hide specific errors and create insecure error handling logic.

Definición

What is CWE-396?

This weakness occurs when code catches a generic exception type like 'Exception' or 'Throwable', which can hide specific errors and create insecure error handling logic.
While it may seem cleaner to catch a broad exception like 'Exception' instead of writing multiple specific catch blocks, this practice is risky. It masks the true nature of errors, preventing you from handling different failure scenarios appropriately. Exceptions that deserve special recovery logic, or that shouldn't be caught at that point in the program, get lumped together and ignored. As your application evolves and starts throwing new, more specific exception types, this broad catch will silently swallow them all. This defeats the core purpose of a typed exception system, making your code less robust and secure over time. It often leads to complex, bug-prone error handling that can introduce vulnerabilities, as critical failures go unnoticed and unlogged.
Impacto en el mundo real

Real-world CVEs caused by CWE-396

Todavía no hay CVEs públicos enlazados a esta CWE en el catálogo de MITRE.

Cómo lo explotan los atacantes

Ruta del atacante paso a paso

  1. 1

    The following code excerpt handles three types of exceptions in an identical fashion.

  2. 2

    At first blush, it may seem preferable to deal with these exceptions in a single catch block, as follows:

  3. 3

    However, if doExchange() is modified to throw a new type of exception that should be handled in some different kind of way, the broad catch block will prevent the compiler from pointing out the situation. Further, the new catch block will now also handle exceptions derived from RuntimeException such as ClassCastException, and NullPointerException, which is not the programmer's intent.

Ejemplo de código vulnerable

Vulnerable Java

At first blush, it may seem preferable to deal with these exceptions in a single catch block, as follows:

Vulnerable Java 
try {
  	doExchange();
  }
  catch (Exception e) {
  	logger.error("doExchange failed", e);
  }
Ejemplo de código seguro

Secure Java

The following code excerpt handles three types of exceptions in an identical fashion.

Seguro Java 
try {
  	doExchange();
  }
  catch (IOException e) {
  	logger.error("doExchange failed", e);
  }
  catch (InvocationTargetException e) {
  		logger.error("doExchange failed", e);
  }
  catch (SQLException e) {
  		logger.error("doExchange failed", e);
  }
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-396

  • Architecture Use safe-by-default frameworks and APIs that prevent the unsafe pattern from being expressible.
  • Implementation Validate input at trust boundaries; use allowlists, not denylists.
  • Implementation Apply the principle of least privilege to credentials, file paths, and runtime permissions.
  • Testing Cover this weakness in CI: SAST rules + targeted unit tests for the data flow.
  • Operation Monitor logs for the runtime signals listed in the next section.
Señales de detección

How to detect CWE-396

Automated Static Analysis High

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Auto-corrección de Plexicus

Plexicus detecta automáticamente CWE-396 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.

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Preguntas frecuentes

Frequently asked questions

¿Qué es CWE-396?

This weakness occurs when code catches a generic exception type like 'Exception' or 'Throwable', which can hide specific errors and create insecure error handling logic.

¿Qué gravedad tiene CWE-396?

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-396?

MITRE lists the following affected platforms: C++, Java, C#, Python.

¿Cómo puedo prevenir CWE-396?

Use safe-by-default frameworks, validate untrusted input at trust boundaries, and apply the principle of least privilege. Cover the data-flow signature in CI with SAST.

¿Cómo detecta y corrige Plexicus CWE-396?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-396 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-396?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/396.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-396

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Recursos

Further reading

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