CWE-565 Base Incomplet

Reliance on Cookies without Validation and Integrity Checking

This vulnerability occurs when an application uses cookies to make security decisions—like granting access or changing settings—but fails to verify that the cookie data is legitimate, unaltered, and…

Définition

What is CWE-565?

This vulnerability occurs when an application uses cookies to make security decisions—like granting access or changing settings—but fails to verify that the cookie data is legitimate, unaltered, and belongs to the current user.
Cookies are often used to store session identifiers, user preferences, or state information, but they are controlled by the client's browser. When an application blindly trusts cookie values without validating their integrity or checking if they match the authenticated user's session, attackers can forge or manipulate cookies to impersonate other users, escalate privileges, or bypass security controls. To prevent this, developers should treat all client-side data, including cookies, as untrusted input. Implement server-side validation for any cookie used in security decisions, use cryptographically signed or encrypted cookies to prevent tampering, and bind session cookies to specific user attributes (like IP address or user agent) to detect session hijacking attempts.
Vulnerability Diagram CWE-565
Reliance on Cookie Without Validation Attacker forges cookie isAdmin=true; user=alice App logic if (cookie.isAdmin) ok // no signing / HMAC // no server-side session trusts client value Admin access trivially granted Cookie value is treated as authoritative without integrity checks.
Impact réel

Real-world CVEs caused by CWE-565

  • CVE-2008-5784

    e-dating application allows admin privileges by setting the admin cookie to 1.

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

The following code excerpt reads a value from a browser cookie to determine the role of the user.

Vulnérable Java 
Cookie[] cookies = request.getCookies();
  for (int i =0; i< cookies.length; i++) {
  	Cookie c = cookies[i];
  	if (c.getName().equals("role")) {
  		userRole = c.getValue();
  	}
  }
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-565

  • Architecture and Design Avoid using cookie data for a security-related decision.
  • Implementation Perform thorough input validation (i.e.: server side validation) on the cookie data if you're going to use it for a security related decision.
  • Architecture and Design Add integrity checks to detect tampering.
  • Architecture and Design Protect critical cookies from replay attacks, since cross-site scripting or other attacks may allow attackers to steal a strongly-encrypted cookie that also passes integrity checks. This mitigation applies to cookies that should only be valid during a single transaction or session. By enforcing timeouts, you may limit the scope of an attack. As part of your integrity check, use an unpredictable, server-side value that is not exposed to the client.
Signaux de détection

How to detect CWE-565

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-565 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-565 ?

This vulnerability occurs when an application uses cookies to make security decisions—like granting access or changing settings—but fails to verify that the cookie data is legitimate, unaltered, and belongs to the current user.

Quelle est la gravité de CWE-565 ?

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-565 ?

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-565 ?

Avoid using cookie data for a security-related decision. Perform thorough input validation (i.e.: server side validation) on the cookie data if you're going to use it for a security related decision.

Comment Plexicus détecte et corrige CWE-565 ?

Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-565 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-565 ?

MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/565.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.

Faiblesses associées

Weaknesses related to CWE-565

CWE-642 Parent

External Control of Critical State Data

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CWE-15 Frère

External Control of System or Configuration Setting

This vulnerability occurs when an application allows users to directly modify critical system settings or configuration values from an…

CWE-426 Frère

Untrusted Search Path

This vulnerability occurs when an application relies on an external search path, provided by a user or environment, to find and load…

CWE-472 Frère

External Control of Assumed-Immutable Web Parameter

This vulnerability occurs when a web application incorrectly trusts data that appears to be fixed or hidden from the user, such as values…

CWE-73 Frère

External Control of File Name or Path

This vulnerability occurs when an application uses unvalidated user input to construct file or directory paths for filesystem operations.

CWE-784 Enfant

Reliance on Cookies without Validation and Integrity Checking in a Security Decision

This vulnerability occurs when an application makes security decisions—like granting access or verifying identity—based solely on cookie…

Ressources

Further reading

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