CWE-912 Clase Incompleto

Hidden Functionality

Hidden functionality refers to undocumented features, commands, or code within a product that are not part of its official specification and are not obvious to users or administrators.

Definición

What is CWE-912?

Hidden functionality refers to undocumented features, commands, or code within a product that are not part of its official specification and are not obvious to users or administrators.
This hidden code can take many forms, from seemingly harmless developer shortcuts like hard-coded backdoor accounts to intentionally malicious logic or non-essential 'Easter eggs.' Regardless of intent, this undocumented behavior creates a security blind spot, as it is not accounted for during standard security reviews, testing, or user training. From an attack perspective, hidden functionality expands the product's attack surface, exposing potential weaknesses that attackers can discover and exploit. Even if not easily accessible through normal use, attackers can often trigger this code by manipulating the application's control flow, leading to unauthorized access, data breaches, or system compromise.
Impacto en el mundo real

Real-world CVEs caused by CWE-912

  • Chain: a digital asset management program has an undisclosed backdoor in the legacy version of a PHP script (CWE-912) that could allow an unauthenticated user to export metadata (CWE-306)

  • A wireless access point manual specifies that the only method of configuration is via web interface (CWE-1059), but there is an undisclosed telnet server that was activated by default (CWE-912).

Cómo lo explotan los atacantes

Ruta del atacante paso a paso

  1. 1

    Identifica una ruta de código que maneje entrada no confiable sin validación.

  2. 2

    Crea un payload que ejercite el comportamiento inseguro — inyección, traversal, overflow o abuso de lógica.

  3. 3

    Envía el payload a través de una solicitud normal y observa la reacción de la aplicación.

  4. 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-912

  • Installation Always verify the integrity of the product that is being installed.
  • Testing Conduct a code coverage analysis using live testing, then closely inspect any code that is not covered.
Señales de detección

How to detect CWE-912

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.

CWE-912

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

Frequently asked questions

¿Qué es CWE-912?

Hidden functionality refers to undocumented features, commands, or code within a product that are not part of its official specification and are not obvious to users or administrators.

¿Qué gravedad tiene CWE-912?

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-912?

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

¿Cómo puedo prevenir CWE-912?

Always verify the integrity of the product that is being installed. Conduct a code coverage analysis using live testing, then closely inspect any code that is not covered.

¿Cómo detecta y corrige Plexicus CWE-912?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-912 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-912?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/912.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-912

CWE-684 Padre

Incorrect Provision of Specified Functionality

This weakness occurs when software behaves differently than its documented specifications, which can mislead users and create security…

CWE-1245 Hermano

Improper Finite State Machines (FSMs) in Hardware Logic

This vulnerability occurs when hardware logic contains flawed Finite State Machines (FSMs). Attackers can exploit these design errors to…

CWE-392 Hermano

Missing Report of Error Condition

This vulnerability occurs when a system fails to properly signal that an error has happened. Instead of returning a clear error code,…

CWE-393 Hermano

Return of Wrong Status Code

This vulnerability occurs when a function returns an inaccurate status code or value that misrepresents the actual outcome of an…

CWE-440 Hermano

Expected Behavior Violation

This weakness occurs when a software component, such as a function, API, or feature, fails to act as documented or intended. The system's…

CWE-446 Hermano

UI Discrepancy for Security Feature

This vulnerability occurs when a user interface incorrectly displays a security feature as active or properly configured, misleading users…

CWE-451 Hermano

User Interface (UI) Misrepresentation of Critical Information

This vulnerability occurs when a user interface fails to accurately display or highlight crucial information, potentially misleading users…

CWE-1242 Hijo

Inclusion of Undocumented Features or Chicken Bits

This vulnerability occurs when a hardware device or chip includes undocumented configuration bits (often called 'chicken bits') or hidden…

CWE-506 Hijo

Embedded Malicious Code

This vulnerability occurs when an application or codebase contains intentionally harmful code inserted by a developer or third party.

¿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.

Calificación

Comprueba si el AI Swarm Pentest encaja en tu entorno.

Déjanos el contexto mínimo. Revisaremos el alcance y te indicaremos el siguiente paso comercial.

Antes de enviar — verifica que encajas

0 / 280

Sin compromiso. Si no encajas, te lo decimos.

SAMPLE HANDOVER · ILLUSTRATIVE

Sample evidence handover

A trimmed view of what your team receives at the end of an AI Swarm Pentest engagement. Real engagements include full technical evidence, executive narrative, and a remediation plan.

VALIDATED FINDING Evidence attached

Server-Side Request Forgery in webhooks/receiver

demo-project/sample-app · src/webhooks/receiver.py:42

SeverityHigh CVSS 3.18.6 Priority79 Confirmedvia replay

Untrusted caller-supplied URLs reach an internal egress without an allowlist. Replayed in a sandbox against a fresh authorized target — the same control was validated to fail twice.

REVIEWER-READY REMEDIATION Merge-ready PR

Validate the target URL against an allowlist of permitted hostnames. Reject private/internal IP ranges. Enforce HTTPS only.

plexicus/remediation/webhooks-ssrf 3 changed · 0 new files
42resp = requests.get(target_url)
42+if not is_allowed_host(target_url):
43+  raise WebhookRejected(target_url)
44+resp = requests.get(target_url, timeout=5)
Every engagement hands over:
  • Executive briefing
  • Validated findings list
  • Merge-ready PRs
  • Compliance mapping (NIS2 · DORA · CRA)
Ronda privada Para inversores