CWE-471 Base Borrador

Modification of Assumed-Immutable Data (MAID)

This vulnerability occurs when an application fails to protect data it assumes cannot be changed, allowing an attacker to alter it.

Definición

What is CWE-471?

This vulnerability occurs when an application fails to protect data it assumes cannot be changed, allowing an attacker to alter it.
Many applications rely on specific pieces of data remaining constant for correct and secure operation. When developers mistakenly treat certain inputs as read-only—like hidden form fields, session cookies, or DNS records—they create a weak spot. Attackers can then modify this assumed-immutable data to bypass security checks, escalate privileges, or corrupt application logic. This flaw often stems from misplaced trust in client-side controls or external systems. To prevent it, developers must validate all critical data on the server side, regardless of its perceived source or intended immutability. Never rely on client-side mechanisms like hidden fields or cookies to store security-sensitive values without verification.
Impacto en el mundo real

Real-world CVEs caused by CWE-471

  • Relies on $PHP_SELF variable for authentication.

  • Gain privileges by modifying assumed-immutable code addresses that are accessed by a driver.

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 Java

In the code excerpt below, an array returned by a Java method is modified despite the fact that arrays are mutable.

Vulnerable Java
String[] colors = car.getAllPossibleColors();
  colors[0] = "Red";
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-471

  • Architecture and Design / Operation / Implementation When the data is stored or transmitted through untrusted sources that could modify the data, implement integrity checks to detect unauthorized modification, or store/transmit the data in a trusted location that is free from external influence.
Señales de detección

How to detect CWE-471

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-471

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-471?

This vulnerability occurs when an application fails to protect data it assumes cannot be changed, allowing an attacker to alter it.

¿Qué gravedad tiene CWE-471?

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-471?

MITRE no ha especificado plataformas afectadas para esta CWE — puede aplicar a la mayoría de los stacks de aplicaciones.

¿Cómo puedo prevenir CWE-471?

When the data is stored or transmitted through untrusted sources that could modify the data, implement integrity checks to detect unauthorized modification, or store/transmit the data in a trusted location that is free from external influence.

¿Cómo detecta y corrige Plexicus CWE-471?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-471 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-471?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/471.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-471

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CWE-1229 Hermano

Creation of Emergent Resource

This vulnerability occurs when a system's normal operations unintentionally create new, exploitable resources that attackers can use to…

CWE-1250 Hermano

Improper Preservation of Consistency Between Independent Representations of Shared State

This vulnerability occurs when a system with multiple independent components (like distributed services or separate hardware units) each…

CWE-1329 Hermano

Reliance on Component That is Not Updateable

This vulnerability occurs when a product depends on a component that cannot be updated or patched to fix security flaws or critical bugs.

CWE-221 Hermano

Information Loss or Omission

This weakness occurs when an application fails to log critical security events or records them inaccurately, which can misguide security…

CWE-372 Hermano

Incomplete Internal State Distinction

This vulnerability occurs when an application fails to accurately track its own operational state. The system incorrectly assumes it's in…

CWE-400 Hermano

Uncontrolled Resource Consumption

This vulnerability occurs when an application fails to properly manage a finite resource, allowing an attacker to exhaust it and cause a…

CWE-404 Hermano

Improper Resource Shutdown or Release

This vulnerability occurs when a program fails to properly close or release a system resource—like a file handle, database connection, or…

¿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.

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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