CWE-824 Base Incompleto

Access of Uninitialized Pointer

This vulnerability occurs when a program tries to use a pointer variable before it has been assigned a valid memory address.

Definición

What is CWE-824?

This vulnerability occurs when a program tries to use a pointer variable before it has been assigned a valid memory address.
Using an uninitialized pointer means your code is reading from or writing to a random, unpredictable location in memory. This often crashes the program (causing a denial of service), but it can also lead to strange behavior, data corruption, or the execution of unintended functions if the pointer is called. An attacker who can control or predict what value ends up in that uninitialized pointer gains significant power. By carefully manipulating memory layout, they might steer the pointer to a location of their choosing, potentially enabling code execution, privilege escalation, or other serious security breaches.
Impacto en el mundo real

Real-world CVEs caused by CWE-824

  • CVE-2024-32878

    LLM product has a free of an uninitialized pointer

  • CVE-2019-3836

    Chain: secure communications library does not initialize a local variable for a data structure (CWE-456), leading to access of an uninitialized pointer (CWE-824).

  • CVE-2018-14641

    Chain: C union member is not initialized (CWE-456), leading to access of invalid pointer (CWE-824)

  • CVE-2010-0211

    chain: unchecked return value (CWE-252) leads to free of invalid, uninitialized pointer (CWE-824).

  • CVE-2009-2768

    Pointer in structure is not initialized, leading to NULL pointer dereference (CWE-476) and system crash.

  • CVE-2009-1721

    Free of an uninitialized pointer.

  • CVE-2009-1415

    Improper handling of invalid signatures leads to free of invalid pointer.

  • CVE-2009-0846

    Invalid encoding triggers free of uninitialized pointer.

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-824

  • 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-824

Automated Static Analysis High

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Auto-corrección de Plexicus

Plexicus detecta automáticamente CWE-824 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-824?

This vulnerability occurs when a program tries to use a pointer variable before it has been assigned a valid memory address.

¿Qué gravedad tiene CWE-824?

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-824?

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

¿Cómo puedo prevenir CWE-824?

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-824?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-824 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-824?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/824.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-824

CWE-119 Padre

Improper Restriction of Operations within the Bounds of a Memory Buffer

This vulnerability occurs when software accesses a memory buffer but reads from or writes to a location outside its allocated boundary.…

CWE-120 Hermano

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

This vulnerability occurs when a program copies data from one memory location to another without first verifying that the source data will…

CWE-123 Hermano

Write-what-where Condition

A write-what-where condition occurs when an attacker can control both the data written and the exact memory location where it's written,…

CWE-125 Hermano

Out-of-bounds Read

An out-of-bounds read occurs when software accesses memory outside the boundaries of a buffer, array, or similar data structure, reading…

CWE-130 Hermano

Improper Handling of Length Parameter Inconsistency

This vulnerability occurs when a program reads a structured data packet or message but fails to properly validate that the declared length…

CWE-466 Hermano

Return of Pointer Value Outside of Expected Range

This vulnerability occurs when a function returns a memory pointer that points outside the expected buffer range, potentially exposing…

CWE-786 Hermano

Access of Memory Location Before Start of Buffer

This vulnerability occurs when software attempts to read from or write to a memory location positioned before the official start of a…

CWE-787 Hermano

Out-of-bounds Write

This vulnerability occurs when software incorrectly writes data outside the boundaries of its allocated memory buffer, either beyond the…

CWE-788 Hermano

Access of Memory Location After End of Buffer

This vulnerability occurs when software attempts to read from or write to a memory buffer using an index or pointer that points past the…

Recursos

Further reading

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