CWE-687 Variante Borrador

Function Call With Incorrectly Specified Argument Value

This vulnerability occurs when a function is called with an argument that holds an incorrect or unexpected value, leading to unintended program behavior or security flaws.

Definición

What is CWE-687?

This vulnerability occurs when a function is called with an argument that holds an incorrect or unexpected value, leading to unintended program behavior or security flaws.
Incorrect argument values often happen due to simple mistakes like mixing up parameter order, using hard-coded magic numbers, or passing a variable that hasn't been properly validated. For example, calling a file permission function with a value meant for a buffer size can expose sensitive data or crash the application. These errors are subtle because the code compiles and runs, but the logic is fundamentally broken, creating a gap between what the developer intended and what actually executes. Finding these mismatches manually in a large codebase is like searching for a needle in a haystack. While SAST tools can flag suspicious patterns, Plexicus uses AI to not only detect these flaws but also generate the precise code fix, transforming a generic warning into an actionable correction. This saves significant manual review time and helps ensure that the function receives the exact value it was designed to handle, closing the door on a wide range of downstream vulnerabilities.
Impacto en el mundo real

Real-world CVEs caused by CWE-687

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 Perl

This Perl code intends to record whether a user authenticated successfully or not, and to exit if the user fails to authenticate. However, when it calls ReportAuth(), the third argument is specified as 0 instead of 1, so it does not exit.

Vulnerable Perl 
sub ReportAuth {
  	my ($username, $result, $fatal) = @_;
  	PrintLog("auth: username=%s, result=%d", $username, $result);
  	if (($result ne "success") && $fatal) {
  		die "Failed!\n";
  	}
  }
  sub PrivilegedFunc
  {
  	my $result = CheckAuth($username);
  	ReportAuth($username, $result, 0);
  	DoReallyImportantStuff();
  }
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-687

  • 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-687

Manual Static Analysis

This might require an understanding of intended program behavior or design to determine whether the value is incorrect.

Auto-corrección de Plexicus

Plexicus detecta automáticamente CWE-687 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.

Solicitar demo Probar Plexicus gratis
Preguntas frecuentes

Frequently asked questions

¿Qué es CWE-687?

This vulnerability occurs when a function is called with an argument that holds an incorrect or unexpected value, leading to unintended program behavior or security flaws.

¿Qué gravedad tiene CWE-687?

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-687?

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

¿Cómo puedo prevenir CWE-687?

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-687?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-687 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-687?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/687.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-687

CWE-628 Padre

Function Call with Incorrectly Specified Arguments

This weakness occurs when a function is called with arguments that are incorrectly specified, causing the function to behave in an…

CWE-683 Hermano

Function Call With Incorrect Order of Arguments

This vulnerability occurs when a program calls a function but supplies the arguments in the wrong order, which can cause unexpected…

CWE-685 Hermano

Function Call With Incorrect Number of Arguments

This weakness occurs when a program calls a function, method, or subroutine but provides the wrong number of arguments—either too many or…

CWE-686 Hermano

Function Call With Incorrect Argument Type

This vulnerability occurs when a program calls a function or method but passes an argument of the wrong data type, which can cause…

CWE-688 Hermano

Function Call With Incorrect Variable or Reference as Argument

This vulnerability occurs when a function is called with the wrong variable or reference passed as an argument. This simple coding mistake…

CWE-560 Hijo

Use of umask() with chmod-style Argument

This vulnerability occurs when a program incorrectly uses the `umask()` system call with an argument formatted for `chmod()`, leading to…

Recursos

Further reading

Listo cuando tú lo estés

Deja de pagar por desarrollador.
Empieza a cerrar el bucle.

Plexicus es el ASPM nativo de IA que escanea, filtra, corrige, pentestea y explica — de forma autónoma. Desarrolladores ilimitados, repos ilimitados, acciones de IA de uso justo. Nivel gratuito real, €269/mo anual cuando estés listo.

Comenzar gratis Reservar una demo