CWE-823 Base Incomplet

Use of Out-of-range Pointer Offset

This vulnerability occurs when a program calculates a new memory address using a valid pointer and an offset, but the resulting address points outside the intended, safe memory region, such as…

Définition

What is CWE-823?

This vulnerability occurs when a program calculates a new memory address using a valid pointer and an offset, but the resulting address points outside the intended, safe memory region, such as beyond the bounds of an array or structure.
Pointers are designed to reference memory, but software logic typically expects them to operate within specific boundaries, like an array's allocated space. When an offset—often from user input, a miscalculation, or corrupted data—pushes the pointer beyond these boundaries, it can read or write to arbitrary, unintended memory locations. An attacker who controls this offset can exploit this to leak sensitive data, corrupt critical program variables, crash the application, or potentially execute malicious code. The core issue is a failure to properly validate that the pointer arithmetic result remains within the legitimate range of the target data structure before it is used.
Impact réel

Real-world CVEs caused by CWE-823

  • CVE-2010-2160

    Invalid offset in undocumented opcode leads to memory corruption.

  • CVE-2010-1281

    Multimedia player uses untrusted value from a file when using file-pointer calculations.

  • CVE-2009-3129

    Spreadsheet program processes a record with an invalid size field, which is later used as an offset.

  • CVE-2009-2694

    Instant messaging library does not validate an offset value specified in a packet.

  • CVE-2009-2687

    Language interpreter does not properly handle invalid offsets in JPEG image, leading to out-of-bounds memory access and crash.

  • CVE-2009-0690

    negative offset leads to out-of-bounds read

  • CVE-2008-4114

    untrusted offset in kernel

  • CVE-2010-2873

    "blind trust" of an offset value while writing heap memory allows corruption of function pointer,leading to code execution

Comment les attaquants l'exploitent

Parcours de l'attaquant étape par étape

  1. 1

    Identifier un chemin de code qui traite des entrées non fiables sans validation.

  2. 2

    Élaborer une charge utile qui exploite le comportement non sécurisé — injection, traversal, débordement ou abus de logique.

  3. 3

    Délivrer la charge utile via une requête normale et observer la réaction de l'application.

  4. 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.

Vulnérable pseudo 
// 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

Sécurisé 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-823

  • 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-823

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.)

Correction automatique Plexicus

Plexicus détecte automatiquement CWE-823 et ouvre une PR de correction en moins de 60 secondes.

Codex Remedium analyse chaque commit, identifie cette faiblesse précise et livre une pull request prête à être relue avec le correctif. Pas de tickets. Pas de transferts.

Obtenir une démo Essayer Plexicus gratuitement
Questions fréquentes

Frequently asked questions

Qu'est-ce que CWE-823 ?

This vulnerability occurs when a program calculates a new memory address using a valid pointer and an offset, but the resulting address points outside the intended, safe memory region, such as beyond the bounds of an array or structure.

Quelle est la gravité de CWE-823 ?

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-823 ?

MITRE n'a pas spécifié les plateformes affectées pour ce CWE — il peut s'appliquer à la plupart des stacks applicatives.

Comment puis-je prévenir CWE-823 ?

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-823 ?

Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-823 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-823 ?

MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/823.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.

Faiblesses associées

Weaknesses related to CWE-823

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…

Ressources

Further reading

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