Führe statische Analyse (SAST) auf der Codebasis aus und suche im Datenfluss nach dem unsicheren Muster.
CWE-277 Variant Draft
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…
Definition
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.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-277
-
User's umask is used when creating temp files.
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Insecure umask for core dumps [is the umask preserved or assigned?].
Wie Angreifer es ausnutzen
Angreiferpfad Schritt für Schritt
- 1
Identifiziere einen Codepfad, der nicht vertrauenswürdige Eingaben ohne Validierung verarbeitet.
- 2
Erzeuge eine Payload, die das unsichere Verhalten auslöst — Injection, Traversal, Overflow oder Logik-Missbrauch.
- 3
Liefere die Payload über einen normalen Request aus und beobachte die Reaktion der Anwendung.
- 4
Iteriere, bis die Antwort Daten preisgibt, Angreifer-Code ausführt oder Berechtigungen eskaliert.
Verwundbares Codebeispiel
Vulnerable pseudo
MITRE hat kein Codebeispiel für diese CWE veröffentlicht. Das untenstehende Muster ist illustrativ — kanonische Referenzen findest du unter Ressourcen.
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
// Untrusted input flows directly into the sensitive sink.
return executeUnsafe(input);
} Sicheres Codebeispiel
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.
Präventions-Checkliste
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.
Erkennungssignale
How to detect CWE-277
Führe dynamische Application-Security-Tests gegen den Live-Endpoint aus.
Beobachte Runtime-Logs auf ungewöhnliche Exception-Traces, fehlerhafte Eingaben oder Versuche, Autorisierung zu umgehen.
Code Review: Markiere jeden neuen Code, der Eingaben von dieser Oberfläche ohne validierte Framework-Helper verarbeitet.
CWE-277
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.
Häufig gestellte Fragen Was ist CWE-277?
Wie gravierend ist CWE-277?
Welche Sprachen oder Plattformen sind von CWE-277 betroffen?
Wie kann ich CWE-277 verhindern?
Wie erkennt und behebt Plexicus CWE-277?
Wo erfahre ich mehr über CWE-277?
Frequently asked questions
Was ist 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.
Wie gravierend ist CWE-277?
MITRE hat für diese Schwachstelle keine Exploit-Wahrscheinlichkeit veröffentlicht. Behandle sie als mittlere Auswirkung, bis dein Threat Model anderes belegt.
Welche Sprachen oder Plattformen sind von CWE-277 betroffen?
MITRE hat für diese CWE keine betroffenen Plattformen spezifiziert — sie kann in den meisten Anwendungs-Stacks auftreten.
Wie kann ich CWE-277 verhindern?
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…
Wie erkennt und behebt Plexicus CWE-277?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-277 bei jedem Commit. Bei einem Treffer öffnet unser Codex-Remedium-Agent einen Fix-PR mit korrigiertem Code, Tests und einer einzeiligen Zusammenfassung für den Reviewer.
Wo erfahre ich mehr über CWE-277?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/277.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
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 Sibling
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 Sibling
Incorrect Default Permissions
This vulnerability occurs when software installation scripts set overly permissive file or directory access rights by default. Instead of…
CWE-278 Sibling
Insecure Preserved Inherited Permissions
This vulnerability occurs when a software product copies or extracts files while unintentionally preserving insecure permissions from…
CWE-279 Sibling
Incorrect Execution-Assigned Permissions
This vulnerability occurs when a running application incorrectly changes an object's access permissions, overriding the security settings…
CWE-281 Sibling
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 Sibling
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…
Ressourcen
Further reading
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Bereit zu validieren, was zählt.
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