CWE-464 Base Incompleto High likelihood

Addition of Data Structure Sentinel

This vulnerability occurs when a program unintentionally adds or modifies a special marker, known as a sentinel, within a data structure, leading to critical logic errors.

Definición

What is CWE-464?

This vulnerability occurs when a program unintentionally adds or modifies a special marker, known as a sentinel, within a data structure, leading to critical logic errors.
Data structures often use sentinel values as internal markers to define their boundaries or format. Common examples include the null terminator ('\0') at the end of a string or a special node marking the end of a linked list. These sentinels are control mechanisms for the program itself, not regular data. If an attacker or a logic flaw can inject or alter these markers, the program's fundamental understanding of its own data breaks down. To prevent this, you must rigorously validate all external inputs and implement strict bounds checking to ensure sentinel values are never written into data fields where they don't belong. Treat sentinels as reserved, protected control characters that your data processing logic must explicitly guard against, separating the trusted internal structure of your data from untrusted, user-supplied content.
Impacto en el mundo real

Real-world CVEs caused by CWE-464

Todavía no hay CVEs públicos enlazados a esta CWE en el catálogo de MITRE.

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 C

The following example assigns some character values to a list of characters and prints them each individually, and then as a string. The third character value is intended to be an integer taken from user input and converted to an int.

Vulnerable C
char *foo;
  foo=malloc(sizeof(char)*5);
  foo[0]='a';
  foo[1]='a';
  foo[2]=fgetc(stdin);
  foo[3]='c';
  foo[4]='\0';
  printf("%c %c %c %c %c \n",foo[0],foo[1],foo[2],foo[3],foo[4]);
  printf("%s\n",foo);
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-464

  • Implementation / Architecture and Design Encapsulate the user from interacting with data sentinels. Validate user input to verify that sentinels are not present.
  • Implementation Proper error checking can reduce the risk of inadvertently introducing sentinel values into data. For example, if a parsing function fails or encounters an error, it might return a value that is the same as the sentinel.
  • Architecture and Design Use an abstraction library to abstract away risky APIs. This is not a complete solution.
  • Operation Use OS-level preventative functionality. This is not a complete solution.
Señales de detección

How to detect CWE-464

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-464

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-464?

This vulnerability occurs when a program unintentionally adds or modifies a special marker, known as a sentinel, within a data structure, leading to critical logic errors.

¿Qué gravedad tiene CWE-464?

MITRE califica la probabilidad de explotación como Alta — esta debilidad se explota activamente en la práctica y debe priorizarse para su remediación.

¿Qué lenguajes o plataformas se ven afectados por CWE-464?

MITRE lists the following affected platforms: C, C++.

¿Cómo puedo prevenir CWE-464?

Encapsulate the user from interacting with data sentinels. Validate user input to verify that sentinels are not present. Proper error checking can reduce the risk of inadvertently introducing sentinel values into data. For example, if a parsing function fails or encounters an error, it might return a value that is the same as the sentinel.

¿Cómo detecta y corrige Plexicus CWE-464?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-464 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-464?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/464.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-464

CWE-138 Padre

Improper Neutralization of Special Elements

This vulnerability occurs when an application accepts external input but fails to properly sanitize special characters or syntax that have…

CWE-140 Hermano

Improper Neutralization of Delimiters

This vulnerability occurs when an application fails to properly handle or sanitize delimiter characters within data inputs, allowing them…

CWE-147 Hermano

Improper Neutralization of Input Terminators

This vulnerability occurs when an application accepts external input but fails to properly handle special characters that downstream…

CWE-148 Hermano

Improper Neutralization of Input Leaders

This vulnerability occurs when an application fails to properly validate or handle input that begins with special control characters or…

CWE-149 Hermano

Improper Neutralization of Quoting Syntax

This vulnerability occurs when an application fails to properly validate or escape quote characters (like single ' or double " quotes) in…

CWE-150 Hermano

Improper Neutralization of Escape, Meta, or Control Sequences

This vulnerability occurs when an application fails to properly sanitize or escape special character sequences in user-supplied input…

CWE-151 Hermano

Improper Neutralization of Comment Delimiters

This vulnerability occurs when an application accepts user input and fails to properly sanitize characters that can be interpreted as…

CWE-152 Hermano

Improper Neutralization of Macro Symbols

This vulnerability occurs when an application accepts user input containing macro symbols (like those used in templates or configuration…

CWE-153 Hermano

Improper Neutralization of Substitution Characters

This vulnerability occurs when an application accepts user input and fails to properly sanitize special characters that can trigger…

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Listo para validar lo que importa.

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Calificación

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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)
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