CWE-675 Class Draft

Multiple Operations on Resource in Single-Operation Context

This vulnerability occurs when a software component performs the same action on a resource multiple times, even though the action is designed to be executed only once. This redundant execution can…

Definition

What is CWE-675?

This vulnerability occurs when a software component performs the same action on a resource multiple times, even though the action is designed to be executed only once. This redundant execution can lead to unintended side effects, data corruption, or resource exhaustion.

Think of this like accidentally hitting 'send' on an email twice. The core issue is that a function or method lacks a proper guard to prevent re-execution on the same target. This often happens in event handlers that don't debounce user clicks, in loops with flawed termination conditions, or when cleanup and initialization routines incorrectly overlap. The duplicate operations waste system resources and can put the application or data into an inconsistent, unpredictable state. For developers, the fix involves implementing idempotence—ensuring an operation produces the same result whether it's run once or multiple times. This can be achieved by using flags to track completion, employing atomic operations, or designing APIs that safely handle repeated calls. Thorough testing with edge cases, especially around user interactions and error recovery paths, is crucial to catch this subtle but impactful flaw.

Auswirkungen in der Praxis

Real-world CVEs caused by CWE-675

CVE-2009-0935

Attacker provides invalid address to a memory-reading function, causing a mutex to be unlocked twice
CVE-2019-13351

file descriptor double close can cause the wrong file to be associated with a file descriptor.
CVE-2004-1939

XSS protection mechanism attempts to remove "/" that could be used to close tags, but it can be bypassed using double encoded slashes (%252F)

Wie Angreifer es ausnutzen

Angreiferpfad Schritt für Schritt

1
The following code shows a simple example of a double free vulnerability.
2
Double free vulnerabilities have two common (and sometimes overlapping) causes:
3
- Error conditions and other exceptional circumstances - Confusion over which part of the program is responsible for freeing the memory
4
Although some double free vulnerabilities are not much more complicated than this example, most are spread out across hundreds of lines of code or even different files. Programmers seem particularly susceptible to freeing global variables more than once.
5
This code binds a server socket to port 21, allowing the server to listen for traffic on that port.

Verwundbares Codebeispiel

Vulnerable C

The following code shows a simple example of a double free vulnerability.

Verwundbar C

char* ptr = (char*)malloc (SIZE);
  ...
  if (abrt) {
  	free(ptr);
  }
  ...
  free(ptr);

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-675

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-675

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-675 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-675?

Wie gravierend ist CWE-675?

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-675 betroffen?

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

Wie kann ich CWE-675 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-675?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-675 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-675?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/675.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-675

CWE-573 Parent

Improper Following of Specification by Caller

This weakness occurs when software fails to properly follow the documented rules, protocols, or requirements of an external component it…

CWE-103 Sibling

Struts: Incomplete validate() Method Definition

This vulnerability occurs in a Struts application when a validator form either completely omits a validate() method or includes one but…

CWE-104 Sibling

Struts: Form Bean Does Not Extend Validation Class

This vulnerability occurs in Apache Struts applications when a form bean class does not properly extend the framework's validation class.…

CWE-243 Sibling

Creation of chroot Jail Without Changing Working Directory

This vulnerability occurs when a program creates a chroot jail but fails to change its current working directory afterward. Because the…

CWE-253 Sibling

Incorrect Check of Function Return Value

This vulnerability occurs when a program misinterprets or improperly validates the return value from a function, causing it to miss…

CWE-296 Sibling

Improper Following of a Certificate's Chain of Trust

This vulnerability occurs when software fails to properly validate the entire certificate chain back to a trusted root authority. This…

CWE-304 Sibling

Missing Critical Step in Authentication

This vulnerability occurs when a software authentication process omits a required step, weakening its overall security.

CWE-325 Sibling

Missing Cryptographic Step

This vulnerability occurs when a software implementation skips a critical step in a cryptographic process, resulting in security that is…

CWE-329 Sibling

Generation of Predictable IV with CBC Mode

This vulnerability occurs when software uses a predictable or reused Initialization Vector (IV) with Cipher Block Chaining (CBC) mode…

Ressourcen

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