CWE-523 Base Incomplete

Unprotected Transport of Credentials

This vulnerability occurs when a login page or authentication system transmits user credentials (like usernames and passwords) over a network without proper encryption, exposing them to interception.

Definition

What is CWE-523?

This vulnerability occurs when a login page or authentication system transmits user credentials (like usernames and passwords) over a network without proper encryption, exposing them to interception.
When credentials travel from a user's browser to your server without encryption, they are sent in plain text. Attackers on the same network can easily intercept this data using simple packet sniffing tools, leading directly to account compromise. This is a fundamental failure to protect the most sensitive part of the user session during its most vulnerable moment—transit. To prevent this, you must enforce the use of strong, modern encryption for all authentication traffic. Always use HTTPS (TLS/SSL) for your entire login process and application, never falling back to HTTP for any requests containing credentials. Additionally, implement HTTP Strict Transport Security (HSTS) to instruct browsers to always use a secure connection, preventing accidental data leakage.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-523

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

Wie Angreifer es ausnutzen

Angreiferpfad Schritt für Schritt

  1. 1

    Identifiziere einen Codepfad, der nicht vertrauenswürdige Eingaben ohne Validierung verarbeitet.

  2. 2

    Erzeuge eine Payload, die das unsichere Verhalten auslöst — Injection, Traversal, Overflow oder Logik-Missbrauch.

  3. 3

    Liefere die Payload über einen normalen Request aus und beobachte die Reaktion der Anwendung.

  4. 4

    Iteriere, bis die Antwort Daten preisgibt, Angreifer-Code ausführt oder Berechtigungen eskaliert.

Verwundbares Codebeispiel

Vulnerable pseudo

MITRE hat kein Codebeispiel für diese CWE veröffentlicht. Das untenstehende Muster ist illustrativ — kanonische Referenzen findest du unter Ressourcen.

Verwundbar pseudo 
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
  // Untrusted input flows directly into the sensitive sink.
  return executeUnsafe(input);
}
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-523

  • Operation / System Configuration Enforce SSL use for the login page or any page used to transmit user credentials or other sensitive information. Even if the entire site does not use SSL, it MUST use SSL for login. Additionally, to help prevent phishing attacks, make sure that SSL serves the login page. SSL allows the user to verify the identity of the server to which they are connecting. If the SSL serves login page, the user can be certain they are talking to the proper end system. A phishing attack would typically redirect a user to a site that does not have a valid trusted server certificate issued from an authorized supplier.
Erkennungssignale

How to detect CWE-523

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-523 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-523?

This vulnerability occurs when a login page or authentication system transmits user credentials (like usernames and passwords) over a network without proper encryption, exposing them to interception.

Wie gravierend ist CWE-523?

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-523 betroffen?

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

Wie kann ich CWE-523 verhindern?

Enforce SSL use for the login page or any page used to transmit user credentials or other sensitive information. Even if the entire site does not use SSL, it MUST use SSL for login. Additionally, to help prevent phishing attacks, make sure that SSL serves the login page. SSL allows the user to verify the identity of the server to which they are connecting. If the SSL serves login page, the user can be certain they are talking to the proper end system. A phishing attack would typically redirect…

Wie erkennt und behebt Plexicus CWE-523?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-523 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-523?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/523.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-523

CWE-522 Parent

Insufficiently Protected Credentials

This vulnerability occurs when an application handles sensitive credentials like passwords or API keys in an insecure way, making them…

CWE-256 Sibling

Plaintext Storage of a Password

This vulnerability occurs when an application stores user passwords as readable text instead of using secure, one-way hashing. This…

CWE-257 Sibling

Storing Passwords in a Recoverable Format

This vulnerability occurs when an application stores user passwords in a format that can be easily reversed or decrypted back to their…

CWE-260 Sibling

Password in Configuration File

This vulnerability occurs when an application stores sensitive passwords directly within a configuration file, making them easily readable…

CWE-261 Sibling

Weak Encoding for Password

Using simple encoding like Base64 to hide a password provides no real security, as it can be easily reversed.

CWE-549 Sibling

Missing Password Field Masking

This vulnerability occurs when an application fails to hide password characters as they are typed, making them visible to anyone who can…

CWE-312 Peer

Cleartext Storage of Sensitive Information

This vulnerability occurs when an application stores sensitive data like passwords, credit card numbers, or personal information in plain…

Ressourcen

Further reading

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