CWE-233 Base Incomplete

Improper Handling of Parameters

This vulnerability occurs when software fails to correctly process input that contains an unexpected number of parameters, missing fields, or undefined arguments. It often leads to crashes,…

Definition

What is CWE-233?

This vulnerability occurs when software fails to correctly process input that contains an unexpected number of parameters, missing fields, or undefined arguments. It often leads to crashes, unexpected behavior, or security bypasses.

At its core, this weakness is about poor input validation and error handling. When an application expects a specific set of data—like form fields, API parameters, or function arguments—but receives fewer, more, or undefined values, it must handle this gracefully. Without proper checks, the software might try to access non-existent data, causing errors like null pointer dereferences, out-of-bounds access, or logic flaws that attackers can exploit to crash the system or bypass security controls. To prevent this, developers should implement strict input validation at all entry points. Always define and enforce the expected structure, count, and presence of all parameters. Use safe access patterns, such as checking for a parameter's existence before using it, and provide default values where appropriate. Robust error handling routines should catch and manage malformed requests without exposing sensitive debug information, ensuring the application remains stable and secure even when faced with unexpected input.

Auswirkungen in der Praxis

Real-world CVEs caused by CWE-233

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

Wie Angreifer es ausnutzen

Angreiferpfad Schritt für Schritt

1
Identifiziere einen Codepfad, der nicht vertrauenswürdige Eingaben ohne Validierung verarbeitet.
2
Erzeuge eine Payload, die das unsichere Verhalten auslöst — Injection, Traversal, Overflow oder Logik-Missbrauch.
3
Liefere die Payload über einen normalen Request aus und beobachte die Reaktion der Anwendung.
4
Iteriere, bis die Antwort Daten preisgibt, Angreifer-Code ausführt oder Berechtigungen eskaliert.

Verwundbares Codebeispiel

Vulnerable Java

This Android application has registered to handle a URL when sent an intent:

Verwundbar Java

```
...* 
  IntentFilter filter = new IntentFilter("com.example.URLHandler.openURL");
  MyReceiver receiver = new MyReceiver();
  registerReceiver(receiver, filter);
  
   *...* 
  
  public class UrlHandlerReceiver extends BroadcastReceiver {
  ```
  		@Override
  		public void onReceive(Context context, Intent intent) {
  				if("com.example.URLHandler.openURL".equals(intent.getAction())) {
  					String URL = intent.getStringExtra("URLToOpen");
  					int length = URL.length();
```
...* 
  				}}}

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-233

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-233

Fuzzing High

Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.

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.)

Plexicus Auto-Fix

Plexicus erkennt CWE-233 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-233?

Wie gravierend ist CWE-233?

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-233 betroffen?

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

Wie kann ich CWE-233 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-233?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-233 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-233?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/233.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-233

CWE-228 Parent

Improper Handling of Syntactically Invalid Structure

This vulnerability occurs when software fails to properly reject or process input that doesn't follow the expected format or structure,…

CWE-166 Sibling

Improper Handling of Missing Special Element

This vulnerability occurs when software expects a specific delimiter, terminator, or other special marker in its input but fails to…

CWE-167 Sibling

Improper Handling of Additional Special Element

This vulnerability occurs when software receives data from another component but fails to properly process or validate unexpected special…

CWE-168 Sibling

Improper Handling of Inconsistent Special Elements

This vulnerability occurs when software fails to correctly process input containing conflicting or mismatched special elements like…

CWE-229 Sibling

Improper Handling of Values

This vulnerability occurs when software fails to correctly process situations where input contains too few values, too many values, or…

CWE-237 Sibling

Improper Handling of Structural Elements

This vulnerability occurs when an application fails to properly validate, sanitize, or interpret the complex internal parts of structured…

CWE-241 Sibling

Improper Handling of Unexpected Data Type

This vulnerability occurs when software fails to properly validate or safely process data that arrives in an unexpected format. For…

CWE-234 Child

Failure to Handle Missing Parameter

This vulnerability occurs when a function or method receives fewer arguments than it expects. The function will still attempt to process…

CWE-235 Child

Improper Handling of Extra Parameters

This vulnerability occurs when a system fails to properly manage situations where it receives more parameters, fields, or arguments with…

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