CWE-248 Base Borrador

Uncaught Exception

This vulnerability occurs when a function throws an error or exception, but the calling code does not have a proper handler to catch and manage it.

Definición

What is CWE-248?

This vulnerability occurs when a function throws an error or exception, but the calling code does not have a proper handler to catch and manage it.

Uncaught exceptions break the normal flow of your application. Instead of gracefully handling an unexpected condition—like a failed network request, invalid input, or missing file—the program will typically terminate abruptly. This leads to a poor user experience, interrupted operations, and makes debugging more difficult, as the root cause may be obscured by a generic crash. Beyond causing crashes, unhandled exceptions can leak sensitive internal details about your application's structure, such as stack traces, file paths, or even partial data. Attackers can use this information to map your system and plan further exploits. To prevent this, developers should implement strategic try-catch blocks around risky operations and define clear fallback behaviors or user-friendly error messages.

Impacto en el mundo real

Real-world CVEs caused by CWE-248

CVE-2023-41151

SDK for OPC Unified Architecture (OPC UA) server has uncaught exception when a socket is blocked for writing but the server tries to send an error
CVE-2023-21087

Java code in a smartphone OS can encounter a "boot loop" due to an uncaught exception

Cómo lo explotan los atacantes

Ruta del atacante paso a paso

1
The following example attempts to resolve a hostname.
2
A DNS lookup failure will cause the Servlet to throw an exception.
3
The _alloca() function allocates memory on the stack. If an allocation request is too large for the available stack space, _alloca() throws an exception. If the exception is not caught, the program will crash, potentially enabling a denial of service attack. _alloca() has been deprecated as of Microsoft Visual Studio 2005(R). It has been replaced with the more secure _alloca_s().
4
EnterCriticalSection() can raise an exception, potentially causing the program to crash. Under operating systems prior to Windows 2000, the EnterCriticalSection() function can raise an exception in low memory situations. If the exception is not caught, the program will crash, potentially enabling a denial of service attack.

Ejemplo de código vulnerable

Vulnerable Java

The following example attempts to resolve a hostname.

Vulnerable Java

protected void doPost (HttpServletRequest req, HttpServletResponse res) throws IOException {
  	String ip = req.getRemoteAddr();
  	InetAddress addr = InetAddress.getByName(ip);
  	...
  	out.println("hello " + addr.getHostName());
  }

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-248

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-248

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-248 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-248?

This vulnerability occurs when a function throws an error or exception, but the calling code does not have a proper handler to catch and manage it.

¿Qué gravedad tiene CWE-248?

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-248?

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

¿Cómo puedo prevenir CWE-248?

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-248?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-248 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-248?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/248.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

Debilidades relacionadas

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