CWE-396 Base Brouillon

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.

Définition

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.
Impact réel

Real-world CVEs caused by CWE-396

Aucune référence CVE publique n'est liée à ce CWE dans le catalogue MITRE pour le moment.

Comment les attaquants l'exploitent

Parcours de l'attaquant étape par étape

  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.

Exemple de code vulnérable

Vulnerable Java

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

Vulnérable Java 
try {
  	doExchange();
  }
  catch (Exception e) {
  	logger.error("doExchange failed", e);
  }
Exemple de code sécurisé

Secure Java

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

Sécurisé 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.
Liste de contrôle de prévention

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.
Signaux de détection

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.)

Correction automatique Plexicus

Plexicus détecte automatiquement CWE-396 et ouvre une PR de correction en moins de 60 secondes.

Codex Remedium analyse chaque commit, identifie cette faiblesse précise et livre une pull request prête à être relue avec le correctif. Pas de tickets. Pas de transferts.

Obtenir une démo Essayer Plexicus gratuitement
Questions fréquentes

Frequently asked questions

Qu'est-ce que 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.

Quelle est la gravité de CWE-396 ?

MITRE n'a pas publié de note de probabilité d'exploitation pour cette faiblesse. Traitez-la comme un impact moyen jusqu'à ce que votre modèle de menace prouve le contraire.

Quels langages ou plateformes sont affectés par CWE-396 ?

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

Comment puis-je prévenir 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.

Comment Plexicus détecte et corrige CWE-396 ?

Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-396 à chaque commit. Lorsqu'une correspondance est trouvée, notre agent Codex Remedium ouvre une PR de correction avec le code corrigé, les tests et un résumé d'une ligne pour le relecteur.

Où puis-je en savoir plus sur CWE-396 ?

MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/396.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.

Faiblesses associées

Weaknesses related to CWE-396

CWE-705 Parent

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CWE-248 Frère

Uncaught Exception

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J2EE Bad Practices: Use of System.exit()

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CWE-395 Frère

Use of NullPointerException Catch to Detect NULL Pointer Dereference

Using a try-catch block for NullPointerException as a substitute for proper null checks is an anti-pattern. This approach masks the root…

CWE-397 Frère

Declaration of Throws for Generic Exception

This vulnerability occurs when a method is declared to throw an overly broad exception type, such as a generic 'Exception' or 'Throwable'.…

CWE-455 Frère

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Return Inside Finally Block

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Execution After Redirect (EAR)

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Ressources

Further reading

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