CWE-284 Pilar Incompleto

Improper Access Control

The software fails to properly limit who can access a resource, allowing unauthorized users or systems to interact with it.

Definición

What is CWE-284?

The software fails to properly limit who can access a resource, allowing unauthorized users or systems to interact with it.

Access control is a security cornerstone built on three pillars: verifying identity (authentication), checking permissions (authorization), and logging actions (accountability). When any of these fails, attackers can steal data, escalate privileges, run commands, or hide their activity. Weaknesses typically arise in two ways: first, through faulty specification, where resources are misconfigured (like world-writable files) or users are given incorrect privileges. Second, through faulty enforcement, where errors in the code allow users to bypass the intended security rules, even if the policy was correctly defined.

Impacto en el mundo real

Real-world CVEs caused by CWE-284

CVE-2022-24985

A form hosting website only checks the session authentication status for a single form, making it possible to bypass authentication when there are multiple forms
CVE-2022-29238

Access-control setting in web-based document collaboration tool is not properly implemented by the code, which prevents listing hidden directories but does not prevent direct requests to files in those directories.
CVE-2022-23607

Python-based HTTP library did not scope cookies to a particular domain such that "supercookies" could be sent to any domain on redirect
CVE-2021-21972

Chain: Cloud computing virtualization platform does not require authentication for upload of a tar format file (CWE-306), then uses .. path traversal sequences (CWE-23) in the file to access unexpected files, as exploited in the wild per CISA KEV.
CVE-2021-37415

IT management product does not perform authentication for some REST API requests, as exploited in the wild per CISA KEV.
CVE-2021-35033

Firmware for a WiFi router uses a hard-coded password for a BusyBox shell, allowing bypass of authentication through the UART port
CVE-2020-10263

Bluetooth speaker does not require authentication for the debug functionality on the UART port, allowing root shell access
CVE-2020-13927

Default setting in workflow management product allows all API requests without authentication, as exploited in the wild per CISA KEV.

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.

Vulnerable pseudo

// 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

Seguro 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-284

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.

Señales de detección

How to detect CWE-284

SAST High

Ejecuta análisis estático (SAST) sobre el código buscando el patrón inseguro en el flujo de datos.

DAST Moderate

Ejecuta pruebas dinámicas de seguridad de aplicaciones (DAST) contra el endpoint en vivo.

Runtime Moderate

Vigila los logs en tiempo de ejecución para detectar trazas de excepción inusuales, entradas malformadas o intentos de bypass de autorización.

Code review Moderate

Revisión de código: marca cualquier código nuevo que maneje entrada desde esta superficie sin usar los helpers validados del framework.

Auto-corrección de Plexicus

Plexicus detecta automáticamente CWE-284 y abre un PR de corrección en menos de 60 segundos.

Codex Remedium escanea cada commit, identifica esta debilidad concreta y entrega un pull request listo para revisión con el parche. Sin tickets. Sin traspasos.

Solicitar demo Probar Plexicus gratis

Preguntas frecuentes

Frequently asked questions

¿Qué es CWE-284?

The software fails to properly limit who can access a resource, allowing unauthorized users or systems to interact with it.

¿Qué gravedad tiene CWE-284?

MITRE no ha publicado una calificación de probabilidad de explotación para esta debilidad. Trátala como de impacto medio hasta que tu modelo de amenazas demuestre lo contrario.

¿Qué lenguajes o plataformas se ven afectados por CWE-284?

MITRE lists the following affected platforms: Not Technology-Specific, ICS/OT.

¿Cómo puedo prevenir CWE-284?

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…

¿Cómo detecta y corrige Plexicus CWE-284?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-284 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-284?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/284.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-284

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