CWE-1391 Clase Incompleto

Use of Weak Credentials

This vulnerability occurs when a system relies on weak authentication credentials—like default passwords, hard-coded keys, or easily guessable values—that an attacker can deduce, reuse, or predict…

Definición

What is CWE-1391?

This vulnerability occurs when a system relies on weak authentication credentials—like default passwords, hard-coded keys, or easily guessable values—that an attacker can deduce, reuse, or predict without needing to perform a full brute-force attack.
Authentication systems are designed to force attackers into time-consuming brute-force attempts when credentials are unknown. However, when credentials are weak—whether they are static, widely reused, or generated in a predictable pattern—attackers can bypass this protection entirely, gaining unauthorized access with minimal effort. Weak credentials typically fall into three categories: hard-coded (static and unchangeable), default (common across installations but changeable), or predictable (generated using a flawed or guessable method). Even if a unique credential is intended for each deployment, a predictable generation process can still make it vulnerable to efficient guessing attacks, undermining the entire authentication mechanism.
Impacto en el mundo real

Real-world CVEs caused by CWE-1391

  • [REF-1374]

    Chain: JavaScript-based cryptocurrency library can fall back to the insecure Math.random() function instead of reporting a failure (CWE-392), thus reducing the entropy (CWE-332) and leading to generation of non-unique cryptographic keys for Bitcoin wallets (CWE-1391)

  • CVE-2022-30270

    Remote Terminal Unit (RTU) uses default credentials for some SSH accounts

  • CVE-2022-29965

    Distributed Control System (DCS) uses a deterministic algorithm to generate utility passwords

  • CVE-2022-30271

    Remote Terminal Unit (RTU) uses a hard-coded SSH private key that is likely to be used in typical deployments

  • CVE-2021-38759

    microcontroller board has default password, allowing admin access

  • CVE-2021-41192

    data visualization/sharing package uses default secret keys or cookie values if they are not specified in environment variables

  • CVE-2020-8994

    UART interface for AI speaker uses empty password for root shell

  • CVE-2020-27020

    password manager does not generate cryptographically strong passwords, allowing prediction of passwords using guessable details such as time of generation

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-1391

  • Architecture Use safe-by-default frameworks and APIs that prevent the unsafe pattern from being expressible.
  • Implementation Validate input at trust boundaries; use allowlists, not denylists.
  • Implementation Apply the principle of least privilege to credentials, file paths, and runtime permissions.
  • Testing Cover this weakness in CI: SAST rules + targeted unit tests for the data flow.
  • Operation Monitor logs for the runtime signals listed in the next section.
Señales de detección

How to detect CWE-1391

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-1391 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.

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Preguntas frecuentes

Frequently asked questions

¿Qué es CWE-1391?

This vulnerability occurs when a system relies on weak authentication credentials—like default passwords, hard-coded keys, or easily guessable values—that an attacker can deduce, reuse, or predict without needing to perform a full brute-force attack.

¿Qué gravedad tiene CWE-1391?

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-1391?

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

¿Cómo puedo prevenir CWE-1391?

Use safe-by-default frameworks, validate untrusted input at trust boundaries, and apply the principle of least privilege. Cover the data-flow signature in CI with SAST.

¿Cómo detecta y corrige Plexicus CWE-1391?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-1391 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-1391?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/1391.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-1391

CWE-1390 Padre

Weak Authentication

This vulnerability occurs when a system's login or identity verification process is too easy to bypass or fool. While it attempts to check…

CWE-262 Hermano

Not Using Password Aging

This vulnerability occurs when a system lacks password expiration policies, allowing users to keep the same password indefinitely.

CWE-263 Hermano

Password Aging with Long Expiration

The system enforces password changes, but the time allowed between changes is excessively long, weakening security.

CWE-289 Hermano

Authentication Bypass by Alternate Name

This vulnerability occurs when a system checks access based on a resource or user name, but fails to account for all the different names…

CWE-290 Hermano

Authentication Bypass by Spoofing

This weakness occurs when an application's authentication system can be tricked into accepting forged or manipulated credentials, allowing…

CWE-294 Hermano

Authentication Bypass by Capture-replay

This vulnerability occurs when an attacker can intercept and record legitimate authentication traffic, then replay it later to gain…

CWE-301 Hermano

Reflection Attack in an Authentication Protocol

A reflection attack is a flaw in mutual authentication protocols that allows an attacker to impersonate a legitimate user without knowing…

CWE-302 Hermano

Authentication Bypass by Assumed-Immutable Data

This vulnerability occurs when an authentication system incorrectly treats certain data as unchangeable, when in fact an attacker can…

CWE-303 Hermano

Incorrect Implementation of Authentication Algorithm

This weakness occurs when a developer implements a standard authentication algorithm, but makes critical mistakes in the code that cause…

Recursos

Further reading

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