CWE-178 Base Incompleto

Improper Handling of Case Sensitivity

This vulnerability occurs when software fails to consistently handle uppercase and lowercase letters when checking or accessing resources, leading to unpredictable behavior and security gaps.

Definición

What is CWE-178?

This vulnerability occurs when software fails to consistently handle uppercase and lowercase letters when checking or accessing resources, leading to unpredictable behavior and security gaps.
When an application treats 'Admin', 'admin', and 'ADMIN' as different entities, it creates inconsistencies that attackers can exploit. For example, a filter blocking 'admin.php' might be bypassed by requesting 'Admin.PHP', or a system might create duplicate user accounts with only case differences, corrupting data integrity. From a security perspective, mishandling case sensitivity weakens defenses. It can drastically reduce password complexity by making 'Password' equivalent to 'password', simplifying brute-force attacks. It also allows attackers to evade security checks by using alternate capitalizations to access restricted files or bypass input validation rules.
Impacto en el mundo real

Real-world CVEs caused by CWE-178

  • CVE-2000-0499

    Application server allows attackers to bypass execution of a jsp page and read the source code using an upper case JSP extension in the request.

  • CVE-2000-0497

    The server is case sensitive, so filetype handlers treat .jsp and .JSP as different extensions. JSP source code may be read because .JSP defaults to the filetype "text".

  • CVE-2000-0498

    The server is case sensitive, so filetype handlers treat .jsp and .JSP as different extensions. JSP source code may be read because .JSP defaults to the filetype "text".

  • CVE-2001-0766

    A URL that contains some characters whose case is not matched by the server's filters may bypass access restrictions because the case-insensitive file system will then handle the request after it bypasses the case sensitive filter.

  • CVE-2001-0795

    Server allows remote attackers to obtain source code of CGI scripts via URLs that contain MS-DOS conventions such as (1) upper case letters or (2) 8.3 file names.

  • CVE-2001-1238

    Task Manager does not allow local users to end processes with uppercase letters named (1) winlogon.exe, (2) csrss.exe, (3) smss.exe and (4) services.exe via the Process tab which could allow local users to install Trojan horses that cannot be stopped.

  • CVE-2003-0411

    chain: Code was ported from a case-sensitive Unix platform to a case-insensitive Windows platform where filetype handlers treat .jsp and .JSP as different extensions. JSP source code may be read because .JSP defaults to the filetype "text".

  • CVE-2002-0485

    Leads to interpretation error

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 Java

In the following example, an XSS neutralization method intends to replace script tags in user-supplied input with a safe equivalent:

Vulnerable Java 
public String preventXSS(String input, String mask) {
  	return input.replaceAll("script", mask);
  }
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-178

  • Architecture and Design Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
  • 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.
  • Implementation Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
Señales de detección

How to detect CWE-178

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-178 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-178?

This vulnerability occurs when software fails to consistently handle uppercase and lowercase letters when checking or accessing resources, leading to unpredictable behavior and security gaps.

¿Qué gravedad tiene CWE-178?

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-178?

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

¿Cómo puedo prevenir CWE-178?

Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names. 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…

¿Cómo detecta y corrige Plexicus CWE-178?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-178 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-178?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/178.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

Weaknesses related to CWE-178

CWE-706 Padre

Use of Incorrectly-Resolved Name or Reference

This vulnerability occurs when software uses a name, path, or reference to access a resource, but that identifier points to something…

CWE-22 Hermano

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

This vulnerability occurs when an application builds a file path using user input but fails to properly validate it, allowing an attacker…

CWE-386 Hermano

Symbolic Name not Mapping to Correct Object

This vulnerability occurs when a program uses a fixed symbolic name (like a constant or identifier) to refer to an object, but that name…

CWE-41 Hermano

Improper Resolution of Path Equivalence

This vulnerability occurs when an application fails to properly handle different text representations that refer to the same file or…

CWE-59 Hermano

Improper Link Resolution Before File Access ('Link Following')

This vulnerability occurs when an application uses a filename to access a file but fails to properly check if that name points to a…

CWE-66 Hermano

Improper Handling of File Names that Identify Virtual Resources

This vulnerability occurs when software incorrectly processes a filename that points to a 'virtual' resource—like a device, pipe, or…

CWE-827 Hermano

Improper Control of Document Type Definition

This vulnerability occurs when an application fails to properly restrict which Document Type Definitions (DTDs) can be referenced during…

CWE-98 Hermano

Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')

This vulnerability occurs when a PHP application uses unvalidated or insufficiently restricted user input directly within file inclusion…

CWE-433 Puede preceder

Unparsed Raw Web Content Delivery

This vulnerability occurs when a web application stores unprocessed files—like configuration scripts or raw source code—in publicly…

Recursos

Further reading

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