CWE-705 Class Incomplete

Incorrect Control Flow Scoping

This vulnerability occurs when a program fails to return execution to the correct point in the code after finishing a specific operation or handling an error. Instead of resuming normal flow, it may…

Definition

What is CWE-705?

This vulnerability occurs when a program fails to return execution to the correct point in the code after finishing a specific operation or handling an error. Instead of resuming normal flow, it may jump to an unintended location, leading to unpredictable behavior or security issues.
Incorrect control flow scoping is like a function not knowing where to go after it completes its job. Common causes include misusing return statements, incorrectly implementing callbacks, or improperly managing error handlers (like try/catch blocks). When the program's execution path doesn't correctly return to its calling context or a designated error-handling routine, it can leave the application in an inconsistent state, skip crucial security checks, or expose internal data. For developers, the main risk is that this flaw often creates subtle bugs that are hard to trace during testing but can be exploited in production. Attackers might manipulate error conditions or specific inputs to hijack the flawed control flow, potentially bypassing authentication, escalating privileges, or causing a crash. To prevent it, always ensure functions and error handlers have explicit, unambiguous return paths and that asynchronous callbacks correctly reintegrate into the main application logic.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-705

  • Java code in a smartphone OS can encounter a "boot loop" due to an uncaught exception

  • chain: incorrect "goto" in Apple SSL product bypasses certificate validation, allowing Adversary-in-the-Middle (AITM) attack (Apple "goto fail" bug). CWE-705 (Incorrect Control Flow Scoping) -> CWE-561 (Dead Code) -> CWE-295 (Improper Certificate Validation) -> CWE-393 (Return of Wrong Status Code) -> CWE-300 (Channel Accessible by Non-Endpoint).

Wie Angreifer es ausnutzen

Angreiferpfad Schritt für Schritt

  1. 1

    The following example attempts to resolve a hostname.

  2. 2

    A DNS lookup failure will cause the Servlet to throw an exception.

  3. 3

    This code queries a server and displays its status when a request comes from an authorized IP address.

  4. 4

    This code redirects unauthorized users, but continues to execute code after calling http_redirect(). This means even unauthorized users may be able to access the contents of the page or perform a DoS attack on the server being queried. Also, note that this code is vulnerable to an IP address spoofing attack (CWE-212).

  5. 5

    Included in the doPost() method defined below is a call to System.exit() in the event of a specific exception.

Verwundbares Codebeispiel

Vulnerable Java

The following example attempts to resolve a hostname.

Verwundbar Java
protected void doPost (HttpServletRequest req, HttpServletResponse res) throws IOException {
  	String ip = req.getRemoteAddr();
  	InetAddress addr = InetAddress.getByName(ip);
  	...
  	out.println("hello " + addr.getHostName());
  }
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-705

  • 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-705

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-705 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.

Häufig gestellte Fragen

Frequently asked questions

Was ist CWE-705?

This vulnerability occurs when a program fails to return execution to the correct point in the code after finishing a specific operation or handling an error. Instead of resuming normal flow, it may jump to an unintended location, leading to unpredictable behavior or security issues.

Wie gravierend ist CWE-705?

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-705 betroffen?

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

Wie kann ich CWE-705 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-705?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-705 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-705?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/705.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-705

CWE-691 Parent

Insufficient Control Flow Management

This vulnerability occurs when a program's execution flow isn't properly managed, allowing attackers to bypass critical checks, trigger…

CWE-1265 Sibling

Unintended Reentrant Invocation of Non-reentrant Code Via Nested Calls

This vulnerability occurs when a non-reentrant function is called, and during its execution, another call is triggered that unexpectedly…

CWE-1281 Sibling

Sequence of Processor Instructions Leads to Unexpected Behavior

Certain sequences of valid and invalid processor instructions can cause the CPU to lock up or behave unpredictably, often requiring a hard…

CWE-362 Sibling

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

A race condition occurs when multiple processes or threads access a shared resource simultaneously without proper coordination, creating a…

CWE-430 Sibling

Deployment of Wrong Handler

This vulnerability occurs when a system incorrectly assigns or routes an object to the wrong processing component.

CWE-431 Sibling

Missing Handler

This vulnerability occurs when a software component lacks the necessary code to properly handle an error or unexpected event.

CWE-662 Sibling

Improper Synchronization

This vulnerability occurs when a multi-threaded or multi-process application allows shared resources to be accessed by multiple threads or…

CWE-670 Sibling

Always-Incorrect Control Flow Implementation

This weakness occurs when a section of code is structured in a way that always executes incorrectly, regardless of input or conditions.…

CWE-696 Sibling

Incorrect Behavior Order

This weakness occurs when a system executes multiple dependent actions in the wrong sequence, leading to unexpected and potentially…

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