CWE-941 Base Incomplet

Incorrectly Specified Destination in a Communication Channel

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…

Définition

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.
Impact réel

Real-world CVEs caused by CWE-941

  • composite: NTP feature generates large responses (high amplification factor) with spoofed UDP source addresses.

  • Classic "Smurf" attack, using spoofed ICMP packets to broadcast addresses.

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

Comment les attaquants l'exploitent

Parcours de l'attaquant étape par étape

  1. 1

    Identifier un chemin de code qui traite des entrées non fiables sans validation.

  2. 2

    Élaborer une charge utile qui exploite le comportement non sécurisé — injection, traversal, débordement ou abus de logique.

  3. 3

    Délivrer la charge utile via une requête normale et observer la réaction de l'application.

  4. 4

    Itérer jusqu'à ce que la réponse divulgue des données, exécute le code de l'attaquant ou élève les privilèges.

Exemple de code vulnérable

Vulnerable Python

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

Vulnérable 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)
Exemple de code sécurisé

Secure pseudo

Sécurisé 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.
Liste de contrôle de prévention

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.
Signaux de détection

How to detect CWE-941

SAST High

Exécuter une analyse statique (SAST) sur le code source à la recherche du motif non sécurisé dans le flux de données.

DAST Moderate

Exécuter des tests de sécurité applicative dynamique (DAST) contre le point de terminaison en ligne.

Runtime Moderate

Surveiller les journaux runtime pour détecter des traces d'exception inhabituelles, des entrées malformées ou des tentatives de contournement d'autorisation.

Code review Moderate

Revue de code : signaler tout nouveau code qui traite les entrées de cette surface sans utiliser les helpers du framework validés.

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.

Questions fréquentes

Frequently asked questions

Qu'est-ce que 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.

Quelle est la gravité de CWE-941 ?

MITRE n'a pas publié de note de probabilité d'exploitation pour cette faiblesse. Traitez-la comme un impact moyen jusqu'à ce que votre modèle de menace prouve le contraire.

Quels langages ou plateformes sont affectés par CWE-941 ?

MITRE lists the following affected platforms: Mobile.

Comment puis-je prévenir CWE-941 ?

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.

Comment Plexicus détecte et corrige CWE-941 ?

Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-941 à chaque commit. Lorsqu'une correspondance est trouvée, notre agent Codex Remedium ouvre une PR de correction avec le code corrigé, les tests et un résumé d'une ligne pour le relecteur.

Où puis-je en savoir plus sur CWE-941 ?

MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/941.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.

Faiblesses associées

Weaknesses related to CWE-941

CWE-923 Parent

Improper Restriction of Communication Channel to Intended Endpoints

This vulnerability occurs when a system opens a communication channel for a sensitive task but fails to properly verify that it's actually…

CWE-1275 Frère

Sensitive Cookie with Improper SameSite Attribute

This vulnerability occurs when a sensitive cookie does not have a secure SameSite attribute configured, leaving it exposed to cross-site…

CWE-291 Frère

Reliance on IP Address for Authentication

This vulnerability occurs when a system uses a client's IP address as the sole or primary method to verify their identity.

CWE-297 Frère

Improper Validation of Certificate with Host Mismatch

This vulnerability occurs when an application accepts a valid SSL/TLS certificate without properly verifying that it actually belongs to…

CWE-300 Frère

Channel Accessible by Non-Endpoint

This vulnerability occurs when a system fails to properly verify who is on the other end of a communication link or to secure the channel…

CWE-419 Frère

Unprotected Primary Channel

This vulnerability occurs when an application exposes a privileged administrative interface or restricted functionality through a primary…

CWE-420 Frère

Unprotected Alternate Channel

This vulnerability occurs when an application secures its main communication path but leaves a backup or alternative channel with weaker…

CWE-940 Frère

Improper Verification of Source of a Communication Channel

This vulnerability occurs when an application accepts incoming communication requests without properly checking where they originate from,…

CWE-942 Frère

Permissive Cross-domain Security Policy with Untrusted Domains

This vulnerability occurs when a web application's cross-domain security policy, like a Content Security Policy (CSP), explicitly allows…

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SAMPLE HANDOVER · ILLUSTRATIVE

Sample evidence handover

A trimmed view of what your team receives at the end of an AI Swarm Pentest engagement. Real engagements include full technical evidence, executive narrative, and a remediation plan.

VALIDATED FINDING Evidence attached

Server-Side Request Forgery in webhooks/receiver

demo-project/sample-app · src/webhooks/receiver.py:42

SeverityHigh CVSS 3.18.6 Priority79 Confirmedvia replay

Untrusted caller-supplied URLs reach an internal egress without an allowlist. Replayed in a sandbox against a fresh authorized target — the same control was validated to fail twice.

REVIEWER-READY REMEDIATION Merge-ready PR

Validate the target URL against an allowlist of permitted hostnames. Reject private/internal IP ranges. Enforce HTTPS only.

plexicus/remediation/webhooks-ssrf 3 changed · 0 new files
42resp = requests.get(target_url)
42+if not is_allowed_host(target_url):
43+  raise WebhookRejected(target_url)
44+resp = requests.get(target_url, timeout=5)
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  • Validated findings list
  • Merge-ready PRs
  • Compliance mapping (NIS2 · DORA · CRA)
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