CWE-464 Base Incomplete High likelihood

Addition of Data Structure Sentinel

This vulnerability occurs when a program unintentionally adds or modifies a special marker, known as a sentinel, within a data structure, leading to critical logic errors.

Definition

What is CWE-464?

This vulnerability occurs when a program unintentionally adds or modifies a special marker, known as a sentinel, within a data structure, leading to critical logic errors.
Data structures often use sentinel values as internal markers to define their boundaries or format. Common examples include the null terminator ('\0') at the end of a string or a special node marking the end of a linked list. These sentinels are control mechanisms for the program itself, not regular data. If an attacker or a logic flaw can inject or alter these markers, the program's fundamental understanding of its own data breaks down. To prevent this, you must rigorously validate all external inputs and implement strict bounds checking to ensure sentinel values are never written into data fields where they don't belong. Treat sentinels as reserved, protected control characters that your data processing logic must explicitly guard against, separating the trusted internal structure of your data from untrusted, user-supplied content.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-464

Bisher sind in MITREs Katalog keine öffentlichen CVE-Referenzen mit dieser CWE verknüpft.

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 C

The following example assigns some character values to a list of characters and prints them each individually, and then as a string. The third character value is intended to be an integer taken from user input and converted to an int.

Verwundbar C 
char *foo;
  foo=malloc(sizeof(char)*5);
  foo[0]='a';
  foo[1]='a';
  foo[2]=fgetc(stdin);
  foo[3]='c';
  foo[4]='\0';
  printf("%c %c %c %c %c \n",foo[0],foo[1],foo[2],foo[3],foo[4]);
  printf("%s\n",foo);
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-464

  • Implementation / Architecture and Design Encapsulate the user from interacting with data sentinels. Validate user input to verify that sentinels are not present.
  • Implementation Proper error checking can reduce the risk of inadvertently introducing sentinel values into data. For example, if a parsing function fails or encounters an error, it might return a value that is the same as the sentinel.
  • Architecture and Design Use an abstraction library to abstract away risky APIs. This is not a complete solution.
  • Operation Use OS-level preventative functionality. This is not a complete solution.
Erkennungssignale

How to detect CWE-464

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-464 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-464?

This vulnerability occurs when a program unintentionally adds or modifies a special marker, known as a sentinel, within a data structure, leading to critical logic errors.

Wie gravierend ist CWE-464?

MITRE stuft die Exploit-Wahrscheinlichkeit als hoch ein — diese Schwachstelle wird aktiv in freier Wildbahn ausgenutzt und sollte priorisiert behoben werden.

Welche Sprachen oder Plattformen sind von CWE-464 betroffen?

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

Wie kann ich CWE-464 verhindern?

Encapsulate the user from interacting with data sentinels. Validate user input to verify that sentinels are not present. Proper error checking can reduce the risk of inadvertently introducing sentinel values into data. For example, if a parsing function fails or encounters an error, it might return a value that is the same as the sentinel.

Wie erkennt und behebt Plexicus CWE-464?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-464 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-464?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/464.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-464

CWE-138 Parent

Improper Neutralization of Special Elements

This vulnerability occurs when an application accepts external input but fails to properly sanitize special characters or syntax that have…

CWE-140 Sibling

Improper Neutralization of Delimiters

This vulnerability occurs when an application fails to properly handle or sanitize delimiter characters within data inputs, allowing them…

CWE-147 Sibling

Improper Neutralization of Input Terminators

This vulnerability occurs when an application accepts external input but fails to properly handle special characters that downstream…

CWE-148 Sibling

Improper Neutralization of Input Leaders

This vulnerability occurs when an application fails to properly validate or handle input that begins with special control characters or…

CWE-149 Sibling

Improper Neutralization of Quoting Syntax

This vulnerability occurs when an application fails to properly validate or escape quote characters (like single ' or double " quotes) in…

CWE-150 Sibling

Improper Neutralization of Escape, Meta, or Control Sequences

This vulnerability occurs when an application fails to properly sanitize or escape special character sequences in user-supplied input…

CWE-151 Sibling

Improper Neutralization of Comment Delimiters

This vulnerability occurs when an application accepts user input and fails to properly sanitize characters that can be interpreted as…

CWE-152 Sibling

Improper Neutralization of Macro Symbols

This vulnerability occurs when an application accepts user input containing macro symbols (like those used in templates or configuration…

CWE-153 Sibling

Improper Neutralization of Substitution Characters

This vulnerability occurs when an application accepts user input and fails to properly sanitize special characters that can trigger…

Ressourcen

Further reading

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