CWE-822 Base Incomplete

Untrusted Pointer Dereference

This vulnerability occurs when software takes a value from an untrusted source, treats it as a memory address (a pointer), and then accesses that memory location directly for reading or writing.

Definition

What is CWE-822?

This vulnerability occurs when software takes a value from an untrusted source, treats it as a memory address (a pointer), and then accesses that memory location directly for reading or writing.
An attacker can exploit this by providing a pointer to unexpected memory regions. If the software writes to this location, it could corrupt critical data, crash the program, or even allow code execution. If it reads from the location, it might leak sensitive information, cause a crash, or use an arbitrary value from memory, leading to unpredictable behavior. This weakness appears in several forms. For example, the untrusted value might be called directly as a function pointer. In operating system kernels, untrusted pointers can cross the boundary from user space into privileged memory via system calls. It also often arises when code designed for a trusted, isolated environment is later exposed to untrusted network input without proper validation of pointer values.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-822

  • CVE-2007-5655

    message-passing framework interprets values in packets as pointers, causing a crash.

  • CVE-2010-2299

    labeled as a "type confusion" issue, also referred to as a "stale pointer." However, the bug ID says "contents are simply interpreted as a pointer... renderer ordinarily doesn't supply this pointer directly". The "handle" in the untrusted area is replaced in one function, but not another - thus also, effectively, exposure to wrong sphere (CWE-668).

  • CVE-2009-1719

    Untrusted dereference using undocumented constructor.

  • CVE-2009-1250

    An error code is incorrectly checked and interpreted as a pointer, leading to a crash.

  • CVE-2009-0311

    An untrusted value is obtained from a packet and directly called as a function pointer, leading to code execution.

  • CVE-2010-1818

    Undocumented attribute in multimedia software allows "unmarshaling" of an untrusted pointer.

  • CVE-2010-3189

    ActiveX control for security software accepts a parameter that is assumed to be an initialized pointer.

  • CVE-2010-1253

    Spreadsheet software treats certain record values that lead to "user-controlled pointer" (might be untrusted offset, not untrusted pointer).

Wie Angreifer es ausnutzen

Angreiferpfad Schritt für Schritt

  1. 1

    Identifiziere einen Codepfad, der nicht vertrauenswürdige Eingaben ohne Validierung verarbeitet.

  2. 2

    Erzeuge eine Payload, die das unsichere Verhalten auslöst — Injection, Traversal, Overflow oder Logik-Missbrauch.

  3. 3

    Liefere die Payload über einen normalen Request aus und beobachte die Reaktion der Anwendung.

  4. 4

    Iteriere, bis die Antwort Daten preisgibt, Angreifer-Code ausführt oder Berechtigungen eskaliert.

Verwundbares Codebeispiel

Vulnerable pseudo

MITRE hat kein Codebeispiel für diese CWE veröffentlicht. Das untenstehende Muster ist illustrativ — kanonische Referenzen findest du unter Ressourcen.

Verwundbar pseudo 
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
  // Untrusted input flows directly into the sensitive sink.
  return executeUnsafe(input);
}
Sicheres Codebeispiel

Secure pseudo

Sicher 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.
Präventions-Checkliste

How to prevent CWE-822

  • 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.
Erkennungssignale

How to detect CWE-822

SAST High

Führe statische Analyse (SAST) auf der Codebasis aus und suche im Datenfluss nach dem unsicheren Muster.

DAST Moderate

Führe dynamische Application-Security-Tests gegen den Live-Endpoint aus.

Runtime Moderate

Beobachte Runtime-Logs auf ungewöhnliche Exception-Traces, fehlerhafte Eingaben oder Versuche, Autorisierung zu umgehen.

Code review Moderate

Code Review: Markiere jeden neuen Code, der Eingaben von dieser Oberfläche ohne validierte Framework-Helper verarbeitet.

Plexicus Auto-Fix

Plexicus erkennt CWE-822 automatisch und öffnet in unter 60 Sekunden einen Fix-PR.

Codex Remedium scannt jeden Commit, identifiziert genau diese Schwachstelle und liefert einen reviewer-ready Pull Request mit dem Patch. Keine Tickets. Keine Hand-offs.

Demo anfordern Plexicus kostenlos testen
Häufig gestellte Fragen

Frequently asked questions

Was ist CWE-822?

This vulnerability occurs when software takes a value from an untrusted source, treats it as a memory address (a pointer), and then accesses that memory location directly for reading or writing.

Wie gravierend ist CWE-822?

MITRE hat für diese Schwachstelle keine Exploit-Wahrscheinlichkeit veröffentlicht. Behandle sie als mittlere Auswirkung, bis dein Threat Model anderes belegt.

Welche Sprachen oder Plattformen sind von CWE-822 betroffen?

MITRE hat für diese CWE keine betroffenen Plattformen spezifiziert — sie kann in den meisten Anwendungs-Stacks auftreten.

Wie kann ich CWE-822 verhindern?

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.

Wie erkennt und behebt Plexicus CWE-822?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-822 bei jedem Commit. Bei einem Treffer öffnet unser Codex-Remedium-Agent einen Fix-PR mit korrigiertem Code, Tests und einer einzeiligen Zusammenfassung für den Reviewer.

Wo erfahre ich mehr über CWE-822?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/822.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-822

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 Sibling

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 Sibling

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 Sibling

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 Sibling

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 Sibling

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 Sibling

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 Sibling

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 Sibling

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…

Ressourcen

Further reading

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