CWE-268 Base Brouillon High likelihood

Privilege Chaining

Privilege chaining occurs when an attacker combines two separate permissions or capabilities, neither of which is dangerous on its own, to perform a harmful action that neither permission should…

Définition

What is CWE-268?

Privilege chaining occurs when an attacker combines two separate permissions or capabilities, neither of which is dangerous on its own, to perform a harmful action that neither permission should individually allow.
This vulnerability is like a security bypass puzzle. A system might correctly enforce that a user cannot directly delete a file or directly write to a system directory. However, if the user can first move a file into that protected directory (using one permission) and then delete any file they own there (using a second permission), they have effectively achieved an unauthorized deletion. The core failure is that the system's security checks evaluate each privilege in isolation, missing the dangerous sequence they enable when used together. To prevent this, developers must design authorization checks that consider context and history, not just the immediate action. This involves analyzing how privileges can interact over a session or transaction. Implementing mandatory access control (MAC), logging and monitoring for unusual privilege sequences, and adhering to the principle of least privilege are key defenses. Always ask: 'Could these two allowed actions be combined to achieve something we explicitly forbid?'
Impact réel

Real-world CVEs caused by CWE-268

  • CVE-2005-1736

    Chaining of user rights.

  • CVE-2002-1772

    Gain certain rights via privilege chaining in alternate channel.

  • CVE-2005-1973

    Application is allowed to assign extra permissions to itself.

  • CVE-2003-0640

    "operator" user can overwrite usernames and passwords to gain admin privileges.

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 Java

This code allows someone with the role of "ADMIN" or "OPERATOR" to reset a user's password. The role of "OPERATOR" is intended to have less privileges than an "ADMIN", but still be able to help users with small issues such as forgotten passwords.

Vulnérable Java 
public enum Roles {
  	ADMIN,OPERATOR,USER,GUEST
  }
  public void resetPassword(User requestingUser, User user, String password ){
  		if(isAuthenticated(requestingUser)){
  				switch(requestingUser.role){
  						case GUEST:
  							System.out.println("You are not authorized to perform this command");
  							break;
  						case USER:
  							System.out.println("You are not authorized to perform this command");
  							break;
  						default:
  							setPassword(user,password);
  							break;
  						}
  				}
  		else{
  			System.out.println("You must be logged in to perform this command");
  		}
  }
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-268

  • Architecture and Design Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
  • 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.
Signaux de détection

How to detect CWE-268

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-268 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-268 ?

Privilege chaining occurs when an attacker combines two separate permissions or capabilities, neither of which is dangerous on its own, to perform a harmful action that neither permission should individually allow.

Quelle est la gravité de CWE-268 ?

MITRE évalue la probabilité d'exploitation comme Élevée — cette faiblesse est activement exploitée et doit être priorisée pour la remédiation.

Quels langages ou plateformes sont affectés par CWE-268 ?

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-268 ?

Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource. Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.

Comment Plexicus détecte et corrige CWE-268 ?

Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-268 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-268 ?

MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/268.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.

Faiblesses associées

Weaknesses related to CWE-268

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-270 Frère

Privilege Context Switching Error

This vulnerability occurs when an application fails to properly manage user permissions while moving between different security contexts,…

CWE-271 Frère

Privilege Dropping / Lowering Errors

This vulnerability occurs when a system or process fails to reduce its elevated permissions before transferring control of a resource to a…

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…

Ressources

Further reading

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