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 Incomplet
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.
Définition
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.
Impact réel
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.
Comment les attaquants l'exploitent
Parcours de l'attaquant étape par étape
- 1
Identifier un chemin de code qui traite des entrées non fiables sans validation.
- 2
Élaborer une charge utile qui exploite le comportement non sécurisé — injection, traversal, débordement ou abus de logique.
- 3
Délivrer la charge utile via une requête normale et observer la réaction de l'application.
- 4
Itérer jusqu'à ce que la réponse divulgue des données, exécute le code de l'attaquant ou élève les privilèges.
Exemple de code vulnérable
Vulnerable pseudo
MITRE n'a pas publié d'exemple de code pour ce CWE. Le motif ci-dessous est illustratif — voir Ressources pour les références canoniques.
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
// Untrusted input flows directly into the sensitive sink.
return executeUnsafe(input);
} Exemple de code sécurisé
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.
Liste de contrôle de prévention
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.
Signaux de détection
How to detect CWE-824
CWE-824
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Questions fréquentes Qu'est-ce que CWE-824 ?
Quelle est la gravité de CWE-824 ?
Quels langages ou plateformes sont affectés par CWE-824 ?
Comment puis-je prévenir CWE-824 ?
Comment Plexicus détecte et corrige CWE-824 ?
Où puis-je en savoir plus sur CWE-824 ?
Frequently asked questions
Qu'est-ce que CWE-824 ?
This vulnerability occurs when a program tries to use a pointer variable before it has been assigned a valid memory address.
Quelle est la gravité de CWE-824 ?
MITRE n'a pas publié de note de probabilité d'exploitation pour cette faiblesse. Traitez-la comme un impact moyen jusqu'à ce que votre modèle de menace prouve le contraire.
Quels langages ou plateformes sont affectés par CWE-824 ?
MITRE lists the following affected platforms: C, C++.
Comment puis-je prévenir 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.
Comment Plexicus détecte et corrige CWE-824 ?
Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-824 à chaque commit. Lorsqu'une correspondance est trouvée, notre agent Codex Remedium ouvre une PR de correction avec le code corrigé, les tests et un résumé d'une ligne pour le relecteur.
Où puis-je en savoir plus sur CWE-824 ?
MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/824.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.
Faiblesses associées
Weaknesses related to CWE-824
CWE-119 Parent
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 Frère
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 Frère
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 Frère
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 Frère
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 Frère
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 Frère
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 Frère
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 Frère
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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