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-647 Variante Incomplet
Use of Non-Canonical URL Paths for Authorization Decisions
This vulnerability occurs when an application's authorization logic relies on specific URL paths but fails to enforce a single, standardized format. Attackers can bypass access controls by using…
Définition
What is CWE-647?
This vulnerability occurs when an application's authorization logic relies on specific URL paths but fails to enforce a single, standardized format. Attackers can bypass access controls by using alternative, equivalent URL formats that the system doesn't recognize as the same protected resource.
Applications often define access rules for specific URLs, but many different URL formats can point to the same page. If the authorization check doesn't first convert URLs to a canonical (standardized) form, attackers can use variations like different character encodings, case changes, IP addresses instead of domain names, trailing slashes, or explicit port numbers to bypass security checks. Each variation appears different to the authorization system while loading the same protected content.
To prevent this, always normalize URLs to a single canonical format before checking permissions. Implement a default-deny approach that rejects any non-standard URL format. This involves stripping unnecessary elements like default ports, removing trailing slashes, converting to lowercase, decoding encoded characters, and resolving hostnames consistently before any authorization decision is made.
Impact réel
Real-world CVEs caused by CWE-647
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 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.
// 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
// 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-647
- Architecture and Design Make access control policy based on path information in canonical form. Use very restrictive regular expressions to validate that the path is in the expected form.
- Architecture and Design Reject all alternate path encodings that are not in the expected canonical form.
Signaux de détection
How to detect CWE-647
CWE-647
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-647 ?
Quelle est la gravité de CWE-647 ?
Quels langages ou plateformes sont affectés par CWE-647 ?
Comment puis-je prévenir CWE-647 ?
Comment Plexicus détecte et corrige CWE-647 ?
Où puis-je en savoir plus sur CWE-647 ?
Frequently asked questions
Qu'est-ce que CWE-647 ?
This vulnerability occurs when an application's authorization logic relies on specific URL paths but fails to enforce a single, standardized format. Attackers can bypass access controls by using alternative, equivalent URL formats that the system doesn't recognize as the same protected resource.
Quelle est la gravité de CWE-647 ?
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-647 ?
MITRE lists the following affected platforms: Web Server.
Comment puis-je prévenir CWE-647 ?
Make access control policy based on path information in canonical form. Use very restrictive regular expressions to validate that the path is in the expected form. Reject all alternate path encodings that are not in the expected canonical form.
Comment Plexicus détecte et corrige CWE-647 ?
Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-647 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-647 ?
MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/647.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.
Faiblesses associées
Weaknesses related to CWE-647
CWE-863 Parent
Incorrect Authorization
This vulnerability occurs when an application checks if a user is allowed to perform an action or access data, but the check is flawed or…
CWE-1244 Frère
Internal Asset Exposed to Unsafe Debug Access Level or State
This vulnerability occurs when a system's debug or test interface supports multiple access levels, but an internal asset is incorrectly…
CWE-551 Frère
Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
This vulnerability occurs when a web server checks access permissions before fully processing and normalizing a URL, potentially allowing…
CWE-639 Frère
Authorization Bypass Through User-Controlled Key
This vulnerability occurs when an application's authorization system fails to verify that a user is allowed to access specific data before…
CWE-804 Frère
Guessable CAPTCHA
This vulnerability occurs when a CAPTCHA challenge is too easy for automated bots to solve, either by guessing or using pattern…
CWE-942 Frère
Permissive Cross-domain Security Policy with Untrusted Domains
This vulnerability occurs when a web application's cross-domain security policy, like a Content Security Policy (CSP), explicitly allows…
Prêt à valider l'essentiel ?
Prêt à valider ce qui compte.
Plexicus est Proof-Driven AppSec : findings validés, compréhension contextuelle et remédiation relue — ancrée dans la preuve, scopée avec vous.