CWE-248 Base Rascunho

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.

Definição

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 no 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

Como os atacantes a exploram

Trajeto do atacante passo a passo

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.

Exemplo de código vulnerável

Vulnerable Java

The following example attempts to resolve a hostname.

Vulnerável Java

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

Exemplo 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 verificação de prevenção

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.

Sinais de deteção

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.)

Correção automática do Plexicus

O Plexicus deteta automaticamente o CWE-248 e abre um PR de correção em menos de 60 segundos.

O Codex Remedium analisa cada commit, identifica esta fraqueza exata e entrega um pull request pronto para revisão com o patch. Sem tickets. Sem transferências.

Obter uma demonstração Experimente o Plexicus gratuitamente

Perguntas frequentes

Frequently asked questions

O que é o 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.

Qual a gravidade do CWE-248?

A MITRE não publicou uma classificação de probabilidade de exploração para esta fraqueza. Trate-a como impacto médio até o seu modelo de ameaças provar o contrário.

Que linguagens ou plataformas são afetadas pelo CWE-248?

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

Como posso prevenir o 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.

Como é que o Plexicus deteta e corrige o CWE-248?

O motor SAST do Plexicus correlaciona a assinatura de fluxo de dados do CWE-248 em cada commit. Quando é encontrada uma correspondência, o nosso agente Codex Remedium abre um PR de correção com o código corrigido, testes e um resumo de uma linha para o revisor.

Onde posso saber mais sobre o CWE-248?

A MITRE publica a definição canónica em https://cwe.mitre.org/data/definitions/248.html. Pode também consultar a documentação da OWASP e do NIST para orientações adjacentes.

Fraquezas relacionadas

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