CWE-941: Incorrectly Specified Destination in a Communication Channel

Definition

What is CWE-941?

This vulnerability occurs when an application establishes an outgoing communication channel but fails to correctly define or enforce the intended recipient. This misdirection can allow data to be sent to an untrusted or malicious destination.

Attackers can exploit this flaw in two primary ways. First, if they can directly control the destination specification—such as in Server-Side Request Forgery (SSRF) or by spoofing UDP packets—they can redirect traffic to systems they control. This is often used to bypass firewalls, mask attack origins, or launch denial-of-service attacks. Second, the flaw can stem from the application itself incorrectly specifying the target due to misconfiguration, faulty parsing (like of email addresses or IPs), or insecure mechanisms like Android's sticky broadcasts. This unintentional misdirection can allow a malicious actor to intercept sensitive data meant for a trusted service, effectively spoofing it.

Auswirkungen in der Praxis

Real-world CVEs caused by CWE-941

CVE-2013-5211

composite: NTP feature generates large responses (high amplification factor) with spoofed UDP source addresses.
CVE-1999-0513

Classic "Smurf" attack, using spoofed ICMP packets to broadcast addresses.
CVE-1999-1379

DNS query with spoofed source address causes more traffic to be returned to spoofed address than was sent by the attacker.

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 Python

This code listens on a port for DNS requests and sends the result to the requesting address.

Verwundbar Python

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  sock.bind( (UDP_IP,UDP_PORT) )
  while true:
  		data = sock.recvfrom(1024)
  		if not data:
  			break
  		(requestIP, nameToResolve) = parseUDPpacket(data)
  		record = resolveName(nameToResolve)
  		sendResponse(requestIP,record)

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-941

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-941

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.

CWE-941

Don't catalog this weakness. Prove it's reachable.

Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.

Request AI Swarm Pentest

Häufig gestellte Fragen

Frequently asked questions

Was ist CWE-941?

This vulnerability occurs when an application establishes an outgoing communication channel but fails to correctly define or enforce the intended recipient. This misdirection can allow data to be sent to an untrusted or malicious destination.

Wie gravierend ist CWE-941?

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-941 betroffen?

MITRE lists the following affected platforms: Mobile.

Wie kann ich CWE-941 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-941?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-941 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-941?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/941.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-941

CWE-923 Parent

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Plexicus ist Proof-Driven AppSec: validierte Funde, kontextuelles Verständnis und geprüfte Remediation — in Evidenz verankert, mit Ihnen gescoped.

Pentest buchen

Incorrectly Specified Destination in a Communication Channel

What is CWE-941?

Real-world CVEs caused by CWE-941

Angreiferpfad Schritt für Schritt

Vulnerable Python

Secure pseudo

How to prevent CWE-941

How to detect CWE-941

Don't catalog this weakness. Prove it's reachable.

Frequently asked questions

Weaknesses related to CWE-941

Improper Restriction of Communication Channel to Intended Endpoints

Sensitive Cookie with Improper SameSite Attribute

Reliance on IP Address for Authentication

Improper Validation of Certificate with Host Mismatch

Channel Accessible by Non-Endpoint

Unprotected Primary Channel

Unprotected Alternate Channel

Improper Verification of Source of a Communication Channel

Permissive Cross-domain Security Policy with Untrusted Domains

Further reading

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Sample evidence handover

Server-Side Request Forgery in `webhooks/receiver`