Exécuter une analyse statique (SAST) sur le code source à la recherche du motif non sécurisé dans le flux de données.
CWE-277 Variante Brouillon
Insecure Inherited Permissions
This vulnerability occurs when an application sets default file or directory permissions that are too permissive, and these insecure settings are automatically passed down to new files or objects…
Définition
What is CWE-277?
This vulnerability occurs when an application sets default file or directory permissions that are too permissive, and these insecure settings are automatically passed down to new files or objects the program creates.
Insecure inherited permissions are a common configuration flaw where the default 'umask' or access control settings on a parent directory are not restrictive enough. When the application creates new files, folders, or other system objects within that environment, they inherit these overly broad permissions. This often means files containing sensitive data like configuration details, logs, or user information become readable or writable by unauthorized users or system processes.
The root cause is typically a failure to explicitly set secure permissions at creation time, relying instead on the system's inherited defaults. Developers must proactively define strict access controls (like read/write for owners only) when creating resources, especially in multi-user environments or on shared hosting. Ignoring this allows attackers or unintended users to view, modify, or delete critical data, leading to information disclosure or system compromise.
Impact réel
Real-world CVEs caused by CWE-277
-
User's umask is used when creating temp files.
-
Insecure umask for core dumps [is the umask preserved or assigned?].
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-277
- Architecture and Design / Operation Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Architecture and Design Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Signaux de détection
How to detect CWE-277
Exécuter des tests de sécurité applicative dynamique (DAST) contre le point de terminaison en ligne.
Surveiller les journaux runtime pour détecter des traces d'exception inhabituelles, des entrées malformées ou des tentatives de contournement d'autorisation.
Revue de code : signaler tout nouveau code qui traite les entrées de cette surface sans utiliser les helpers du framework validés.
CWE-277
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Questions fréquentes Qu'est-ce que CWE-277 ?
Quelle est la gravité de CWE-277 ?
Quels langages ou plateformes sont affectés par CWE-277 ?
Comment puis-je prévenir CWE-277 ?
Comment Plexicus détecte et corrige CWE-277 ?
Où puis-je en savoir plus sur CWE-277 ?
Frequently asked questions
Qu'est-ce que CWE-277 ?
This vulnerability occurs when an application sets default file or directory permissions that are too permissive, and these insecure settings are automatically passed down to new files or objects the program creates.
Quelle est la gravité de CWE-277 ?
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-277 ?
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-277 ?
Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software. Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and…
Comment Plexicus détecte et corrige CWE-277 ?
Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-277 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-277 ?
MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/277.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.
Faiblesses associées
Weaknesses related to CWE-277
CWE-732 Parent
Incorrect Permission Assignment for Critical Resource
This vulnerability occurs when a system grants overly permissive access to a sensitive resource, allowing unauthorized users or processes…
CWE-1004 Frère
Sensitive Cookie Without 'HttpOnly' Flag
This vulnerability occurs when an application stores sensitive data in a cookie but fails to set the 'HttpOnly' flag, leaving the cookie…
CWE-276 Frère
Incorrect Default Permissions
This vulnerability occurs when software installation scripts set overly permissive file or directory access rights by default. Instead of…
CWE-278 Frère
Insecure Preserved Inherited Permissions
This vulnerability occurs when a software product copies or extracts files while unintentionally preserving insecure permissions from…
CWE-279 Frère
Incorrect Execution-Assigned Permissions
This vulnerability occurs when a running application incorrectly changes an object's access permissions, overriding the security settings…
CWE-281 Frère
Improper Preservation of Permissions
This vulnerability occurs when a system fails to correctly maintain file or object permissions during operations like copying, sharing, or…
CWE-766 Frère
Critical Data Element Declared Public
This vulnerability occurs when a critical piece of data—like a variable, field, or class member—is mistakenly declared as public when it…
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