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.)
CWE-501 Base Brouillon
Trust Boundary Violation
This vulnerability occurs when an application incorrectly stores or processes trusted and untrusted data together within the same structure, such as an object, array, or message.
Définition
What is CWE-501?
This vulnerability occurs when an application incorrectly stores or processes trusted and untrusted data together within the same structure, such as an object, array, or message.
Think of a trust boundary as a security checkpoint within your code. Data from untrusted sources (like user input or external APIs) must be validated before it's allowed into the trusted, inner zones of your application where core logic executes. A violation happens when this separation breaks down—trusted and untrusted data are combined in a single structure. This makes it dangerously easy for developers to accidentally treat the entire dataset as safe, bypassing critical validation and leading to injection attacks or data corruption.
Preventing this requires clear architectural separation: validate and sanitize all external data immediately at the entry point, and never merge it with trusted internal data before processing. Managing this at scale across complex applications is difficult; an ASPM like Plexicus can help you visualize these data flows, track trust boundary violations across your entire stack, and prioritize fixes. While SAST tools can flag the pattern, Plexicus uses AI to suggest the specific code changes needed to enforce proper separation, saving hours of manual refactoring work.
Impact réel
Real-world CVEs caused by CWE-501
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
Identifier un chemin de code qui traite des entrées non fiables sans validation.
- 2
Élaborer une charge utile qui exploite le comportement non sécurisé — injection, traversal, débordement ou abus de logique.
- 3
Délivrer la charge utile via une requête normale et observer la réaction de l'application.
- 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 accepts an HTTP request and stores the username parameter in the HTTP session object before checking to ensure that the user has been authenticated.
usrname = request.getParameter("usrname");
if (session.getAttribute(ATTR_USR) == null) {
session.setAttribute(ATTR_USR, usrname);
} Exemple de code sécurisé
Secure 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-501
- 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-501
CWE-501
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Questions fréquentes Qu'est-ce que CWE-501 ?
Quelle est la gravité de CWE-501 ?
Quels langages ou plateformes sont affectés par CWE-501 ?
Comment puis-je prévenir CWE-501 ?
Comment Plexicus détecte et corrige CWE-501 ?
Où puis-je en savoir plus sur CWE-501 ?
Frequently asked questions
Qu'est-ce que CWE-501 ?
This vulnerability occurs when an application incorrectly stores or processes trusted and untrusted data together within the same structure, such as an object, array, or message.
Quelle est la gravité de CWE-501 ?
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-501 ?
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-501 ?
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-501 ?
Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-501 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-501 ?
MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/501.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.
Faiblesses associées
Weaknesses related to CWE-501
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CWE-118 Frère
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CWE-1229 Frère
Creation of Emergent Resource
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CWE-1329 Frère
Reliance on Component That is Not Updateable
This vulnerability occurs when a product depends on a component that cannot be updated or patched to fix security flaws or critical bugs.
CWE-221 Frère
Information Loss or Omission
This weakness occurs when an application fails to log critical security events or records them inaccurately, which can misguide security…
CWE-372 Frère
Incomplete Internal State Distinction
This vulnerability occurs when an application fails to accurately track its own operational state. The system incorrectly assumes it's in…
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Uncontrolled Resource Consumption
This vulnerability occurs when an application fails to properly manage a finite resource, allowing an attacker to exhaust it and cause a…
CWE-404 Frère
Improper Resource Shutdown or Release
This vulnerability occurs when a program fails to properly close or release a system resource—like a file handle, database connection, or…
Ressources
Further reading
- MITRE — CWE-501 officiel https://cwe.mitre.org/data/definitions/501.html
- Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors https://samate.nist.gov/SSATTM_Content/papers/Seven%20Pernicious%20Kingdoms%20-%20Taxonomy%20of%20Sw%20Security%20Errors%20-%20Tsipenyuk%20-%20Chess%20-%20McGraw.pdf
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