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.)
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.
Definição
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 no mundo real
Real-world CVEs caused by CWE-824
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LLM product has a free of an uninitialized pointer
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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).
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Chain: C union member is not initialized (CWE-456), leading to access of invalid pointer (CWE-824)
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chain: unchecked return value (CWE-252) leads to free of invalid, uninitialized pointer (CWE-824).
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Pointer in structure is not initialized, leading to NULL pointer dereference (CWE-476) and system crash.
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Free of an uninitialized pointer.
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Improper handling of invalid signatures leads to free of invalid pointer.
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Invalid encoding triggers free of uninitialized pointer.
Como os atacantes a exploram
Trajeto do atacante passo a passo
- 1
Identificar um caminho de código que trata input não confiável sem validação.
- 2
Criar um payload que explora o comportamento inseguro — injeção, traversal, overflow ou abuso de lógica.
- 3
Entregar o payload através de um pedido normal e observar a reação da aplicação.
- 4
Iterar até que a resposta exponha dados, execute código do atacante ou escale privilégios.
Exemplo de código vulnerável
Vulnerable pseudo
A MITRE não publicou um exemplo de código para este CWE. O padrão abaixo é ilustrativo — consulte os Recursos para referências canónicas.
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
// Untrusted input flows directly into the sensitive sink.
return executeUnsafe(input);
} Exemplo de código seguro
Secure 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-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.
Sinais de deteção
How to detect CWE-824
O Plexicus deteta automaticamente o CWE-824 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.
Perguntas frequentes O que é o CWE-824?
Qual a gravidade do CWE-824?
Que linguagens ou plataformas são afetadas pelo CWE-824?
Como posso prevenir o CWE-824?
Como é que o Plexicus deteta e corrige o CWE-824?
Onde posso saber mais sobre o CWE-824?
Frequently asked questions
O que é o CWE-824?
This vulnerability occurs when a program tries to use a pointer variable before it has been assigned a valid memory address.
Qual a gravidade do CWE-824?
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-824?
MITRE lists the following affected platforms: C, C++.
Como posso prevenir o 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.
Como é que o Plexicus deteta e corrige o CWE-824?
O motor SAST do Plexicus correlaciona a assinatura de fluxo de dados do CWE-824 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-824?
A MITRE publica a definição canónica em https://cwe.mitre.org/data/definitions/824.html. Pode também consultar a documentação da OWASP e do NIST para orientações adjacentes.
Fraquezas relacionadas
Weaknesses related to CWE-824
CWE-119 Pai
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 Irmão
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 Irmão
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 Irmão
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 Irmão
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 Irmão
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 Irmão
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 Irmão
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 Irmão
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…
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