CWE-1287 Base Incompleto

Improper Validation of Specified Type of Input

This vulnerability occurs when software expects a specific type of data as input but fails to properly check that the incoming data actually matches that type.

Definición

What is CWE-1287?

This vulnerability occurs when software expects a specific type of data as input but fails to properly check that the incoming data actually matches that type.

When software doesn't verify that input matches the expected data type, attackers can feed it malformed data. This can trigger system errors, force the application to behave incorrectly, or expose hidden security flaws that would normally be inaccessible with properly typed input. This issue is most common in programming languages that are not strictly type-safe or that allow explicit conversion between data types. Developers must implement explicit validation checks to ensure input conforms to the expected type before processing it, as relying on implicit assumptions creates a significant security gap.

Impacto en el mundo real

Real-world CVEs caused by CWE-1287

CVE-2024-37032

Large language model (LLM) management tool does not validate the format of a digest value (CWE-1287) from a private, untrusted model registry, enabling relative path traversal (CWE-23), a.k.a. Probllama
CVE-2008-2223

SQL injection through an ID that was supposed to be numeric.

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-1287

Implementation Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

Señales de detección

How to detect CWE-1287

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-1287

Don't catalog this weakness. Prove it's reachable.

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Preguntas frecuentes

Frequently asked questions

¿Qué es CWE-1287?

This vulnerability occurs when software expects a specific type of data as input but fails to properly check that the incoming data actually matches that type.

¿Qué gravedad tiene CWE-1287?

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-1287?

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

¿Cómo puedo prevenir CWE-1287?

Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and…

¿Cómo detecta y corrige Plexicus CWE-1287?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-1287 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-1287?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/1287.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-1287

CWE-20 Padre

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Reservar Pentest

Improper Validation of Specified Type of Input

What is CWE-1287?

Real-world CVEs caused by CWE-1287

Ruta del atacante paso a paso

Vulnerable pseudo

Secure pseudo

How to prevent CWE-1287

How to detect CWE-1287

Don't catalog this weakness. Prove it's reachable.

Frequently asked questions

Weaknesses related to CWE-1287

Improper Input Validation

Struts: Duplicate Validation Forms

Struts: Incomplete validate() Method Definition

Struts: Form Bean Does Not Extend Validation Class

Struts: Form Field Without Validator

Struts: Plug-in Framework not in Use

Struts: Unused Validation Form

Struts: Unvalidated Action Form

Struts: Validator Turned Off

Further reading

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Sample evidence handover

Server-Side Request Forgery in `webhooks/receiver`