According to SOAR [REF-1479], the following detection techniques may be useful: ``` Cost effective for partial coverage: ``` Inter-application Flow Analysis
CWE-276 Base Borrador
Incorrect Default Permissions
This vulnerability occurs when software installation scripts set overly permissive file or directory access rights by default. Instead of restricting write access to authorized users or processes,…
Definición
What is CWE-276?
This vulnerability occurs when software installation scripts set overly permissive file or directory access rights by default. Instead of restricting write access to authorized users or processes, the installation allows unintended actors to modify, delete, or corrupt critical application files.
Incorrect default permissions are a common installation-time mistake where files and folders are created with global read/write access (e.g., world-writable). This often happens because the installer runs with elevated privileges but does not properly lock down the resources it deploys. The result is that any user or service on the system, including low-privilege accounts or malware, can alter configuration files, binaries, or libraries, leading to a direct path for privilege escalation, data tampering, or denial of service.
To prevent this, developers and DevOps teams must ensure installation scripts explicitly set secure permissions, adhering to the principle of least privilege. Best practices include removing world-writable bits, assigning ownership to specific service accounts, and validating permissions post-deployment. Automated security scanning tools can also detect and flag overly permissive files as part of a continuous integration pipeline.
Impacto en el mundo real
Real-world CVEs caused by CWE-276
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Executables installed world-writable.
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Home directories installed world-readable.
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World-writable log files allow information loss; world-readable file has cleartext passwords.
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World-readable directory.
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Windows product uses insecure permissions when installing on Solaris (genesis: port error).
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Insecure permissions for a shared secret key file. Overlaps cryptographic problem.
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Default permissions of a device allow IP spoofing.
Cómo lo explotan los atacantes
Ruta del atacante paso a paso
- 1
Identifica una ruta de código que maneje entrada no confiable sin validación.
- 2
Crea un payload que ejercite el comportamiento inseguro — inyección, traversal, overflow o abuso de lógica.
- 3
Envía el payload a través de una solicitud normal y observa la reacción de la aplicación.
- 4
Itera hasta que la respuesta filtre datos, ejecute código del atacante o escale privilegios.
Ejemplo de código vulnerable
Vulnerable pseudo
MITRE no ha publicado un ejemplo de código para esta CWE. El patrón siguiente es ilustrativo — consulta Recursos para referencias canónicas.
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
// Untrusted input flows directly into the sensitive sink.
return executeUnsafe(input);
} Ejemplo de código seguro
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.
Lista de prevención
How to prevent CWE-276
- Architecture and Design / Operation The architecture needs to access and modification attributes for files to only those users who actually require those actions.
- 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.
Señales de detección
How to detect CWE-276
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Cost effective for partial coverage: ``` Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Cost effective for partial coverage: ``` Host-based Vulnerability Scanners - Examine configuration for flaws, verifying that audit mechanisms work, ensure host configuration meets certain predefined criteria Web Application Scanner Web Services Scanner Database Scanners
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Host Application Interface Scanner ``` Cost effective for partial coverage: ``` Fuzz Tester Framework-based Fuzzer Automated Monitored Execution Forced Path Execution
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Manual Source Code Review (not inspections) ``` Cost effective for partial coverage: ``` Focused Manual Spotcheck - Focused manual analysis of source
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Cost effective for partial coverage: ``` Context-configured Source Code Weakness Analyzer
CWE-276
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.
Preguntas frecuentes ¿Qué es CWE-276?
¿Qué gravedad tiene CWE-276?
¿Qué lenguajes o plataformas se ven afectados por CWE-276?
¿Cómo puedo prevenir CWE-276?
¿Cómo detecta y corrige Plexicus CWE-276?
¿Dónde puedo aprender más sobre CWE-276?
Frequently asked questions
¿Qué es CWE-276?
This vulnerability occurs when software installation scripts set overly permissive file or directory access rights by default. Instead of restricting write access to authorized users or processes, the installation allows unintended actors to modify, delete, or corrupt critical application files.
¿Qué gravedad tiene CWE-276?
MITRE califica la probabilidad de explotación como Media — la explotación es realista pero suele requerir condiciones específicas.
¿Qué lenguajes o plataformas se ven afectados por CWE-276?
MITRE lists the following affected platforms: Not Technology-Specific, ICS/OT.
¿Cómo puedo prevenir CWE-276?
The architecture needs to access and modification attributes for files to only those users who actually require those actions. 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…
¿Cómo detecta y corrige Plexicus CWE-276?
El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-276 en cada commit. Cuando hay coincidencia, nuestro agente Codex Remedium abre un PR de corrección con el código corregido, las pruebas y un resumen de una línea para el revisor.
¿Dónde puedo aprender más sobre CWE-276?
MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/276.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.
Debilidades relacionadas
Weaknesses related to CWE-276
CWE-732 Padre
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 Hermano
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-277 Hermano
Insecure Inherited Permissions
This vulnerability occurs when an application sets default file or directory permissions that are too permissive, and these insecure…
CWE-278 Hermano
Insecure Preserved Inherited Permissions
This vulnerability occurs when a software product copies or extracts files while unintentionally preserving insecure permissions from…
CWE-279 Hermano
Incorrect Execution-Assigned Permissions
This vulnerability occurs when a running application incorrectly changes an object's access permissions, overriding the security settings…
CWE-281 Hermano
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 Hermano
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…
Recursos
Further reading
- MITRE — CWE-276 oficial https://cwe.mitre.org/data/definitions/276.html
- State-of-the-Art Resources (SOAR) for Software Vulnerability Detection, Test, and Evaluation https://www.ida.org/-/media/feature/publications/s/st/stateoftheart-resources-soar-for-software-vulnerability-detection-test-and-evaluation/p-5061.ashx
- State-of-the-Art Resources (SOAR) for Software Vulnerability Detection, Test, and Evaluation https://www.ida.org/-/media/feature/publications/s/st/stateoftheart-resources-soar-for-software-vulnerability-detection-test-and-evaluation/p-5061.ashx
¿Listo para validar lo que importa?
Listo para validar lo que importa.
Plexicus es Proof-Driven AppSec: hallazgos validados, comprensión contextual y remediación revisada — anclada en evidencia, acotada contigo.