CWE-270 Base Brouillon

Privilege Context Switching Error

This vulnerability occurs when an application fails to properly manage user permissions while moving between different security contexts, potentially allowing unauthorized actions.

Définition

What is CWE-270?

This vulnerability occurs when an application fails to properly manage user permissions while moving between different security contexts, potentially allowing unauthorized actions.
Think of this as a security guard who forgets to check their keys when moving between restricted areas. In software, this happens when a process or thread switches between different privilege levels—like going from a low-privilege user mode to a high-privilege kernel mode, or when handling data from different trust zones—but doesn't correctly reset or validate its access rights. The system might carry over elevated permissions from a previous task, creating a window where an attacker can execute code or access data they shouldn't have. For developers, the core issue is a broken trust boundary during state transitions. Common pitfalls include temporarily raising privileges for a specific task but failing to drop them immediately afterward, or incorrectly assuming a new context inherits a safe default. To prevent this, always adopt the principle of least privilege explicitly during context switches: deliberately set the required permissions for the new operation and never rely on implicit state. Audit any code that changes execution context, such as system calls, callback handlers, or data parsers, to ensure privilege cleanup is mandatory and fail-safe.
Impact réel

Real-world CVEs caused by CWE-270

  • Web browser cross domain problem when user hits "back" button.

  • Web browser cross domain problem when user hits "back" button.

  • Cross-domain issue - third party product passes code to web browser, which executes it in unsafe zone.

  • Run callback in different security context after it has been changed from untrusted to trusted. * note that "context switch before actions are completed" is one type of problem that happens frequently, espec. in browsers.

Comment les attaquants l'exploitent

Parcours de l'attaquant étape par étape

  1. 1

    Identifier un chemin de code qui traite des entrées non fiables sans validation.

  2. 2

    Élaborer une charge utile qui exploite le comportement non sécurisé — injection, traversal, débordement ou abus de logique.

  3. 3

    Délivrer la charge utile via une requête normale et observer la réaction de l'application.

  4. 4

    Itérer jusqu'à ce que la réponse divulgue des données, exécute le code de l'attaquant ou élève les privilèges.

Exemple de code vulnérable

Vulnerable pseudo

MITRE n'a pas publié d'exemple de code pour ce CWE. Le motif ci-dessous est illustratif — voir Ressources pour les références canoniques.

Vulnérable pseudo
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
  // Untrusted input flows directly into the sensitive sink.
  return executeUnsafe(input);
}
Exemple de code sécurisé

Secure pseudo

Sécurisé 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.
Liste de contrôle de prévention

How to prevent CWE-270

  • Architecture and Design / Operation Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
  • Architecture and Design / Operation Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
  • Architecture and Design Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
Signaux de détection

How to detect CWE-270

SAST High

Exécuter une analyse statique (SAST) sur le code source à la recherche du motif non sécurisé dans le flux de données.

DAST Moderate

Exécuter des tests de sécurité applicative dynamique (DAST) contre le point de terminaison en ligne.

Runtime Moderate

Surveiller les journaux runtime pour détecter des traces d'exception inhabituelles, des entrées malformées ou des tentatives de contournement d'autorisation.

Code review Moderate

Revue de code : signaler tout nouveau code qui traite les entrées de cette surface sans utiliser les helpers du framework validés.

Correction automatique Plexicus

Plexicus détecte automatiquement CWE-270 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.

Questions fréquentes

Frequently asked questions

Qu'est-ce que CWE-270 ?

This vulnerability occurs when an application fails to properly manage user permissions while moving between different security contexts, potentially allowing unauthorized actions.

Quelle est la gravité de CWE-270 ?

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-270 ?

MITRE n'a pas spécifié les plateformes affectées pour ce CWE — il peut s'appliquer à la plupart des stacks applicatives.

Comment puis-je prévenir CWE-270 ?

Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software. Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need…

Comment Plexicus détecte et corrige CWE-270 ?

Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-270 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-270 ?

MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/270.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.

Faiblesses associées

Weaknesses related to CWE-270

CWE-269 Parent

Improper Privilege Management

This vulnerability occurs when an application fails to correctly manage user permissions, allowing someone to perform actions or access…

CWE-250 Frère

Execution with Unnecessary Privileges

This vulnerability occurs when software runs with higher permissions than it actually needs to perform its tasks. This excessive privilege…

CWE-266 Frère

Incorrect Privilege Assignment

This vulnerability occurs when a system mistakenly grants a user, process, or entity a specific permission or privilege they should not…

CWE-267 Frère

Privilege Defined With Unsafe Actions

This vulnerability occurs when a system grants a user, role, or process a specific permission that can be misused to perform dangerous,…

CWE-268 Frère

Privilege Chaining

Privilege chaining occurs when an attacker combines two separate permissions or capabilities, neither of which is dangerous on its own, to…

CWE-271 Frère

Privilege Dropping / Lowering Errors

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CWE-274 Frère

Improper Handling of Insufficient Privileges

This vulnerability occurs when an application fails to properly manage situations where it lacks the necessary permissions to execute an…

CWE-648 Frère

Incorrect Use of Privileged APIs

This vulnerability occurs when software incorrectly uses functions that require special permissions. Attackers can exploit these mistakes…

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