CWE-1390 Class Incomplete

Weak Authentication

This vulnerability occurs when a system's login or identity verification process is too easy to bypass or fool. While it attempts to check who a user claims to be, the checks are insufficient,…

Definition

What is CWE-1390?

This vulnerability occurs when a system's login or identity verification process is too easy to bypass or fool. While it attempts to check who a user claims to be, the checks are insufficient, allowing attackers to impersonate legitimate users.
Weak authentication creates a critical security gap by failing to reliably verify user identity. Attackers can exploit this flaw using methods like brute-forcing simple passwords, reusing stolen credentials, or bypassing login pages entirely, often with minimal time or resources. This undermines the entire security model, as access controls are built on the faulty assumption that the user's identity is proven. For developers, this means your authentication mechanism must actively resist common attacks. Implement strong, multi-factor authentication (MFA), enforce robust password policies, and use secure, time-limited sessions. Regularly audit and test your login flows to ensure they cannot be circumvented with automated tools or known exploitation techniques.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-1390

  • CVE-2022-30034

    Chain: Web UI for a Python RPC framework does not use regex anchors to validate user login emails (CWE-777), potentially allowing bypass of OAuth (CWE-1390).

  • CVE-2022-35248

    Chat application skips validation when Central Authentication Service (CAS) is enabled, effectively removing the second factor from two-factor authentication

  • CVE-2021-3116

    Chain: Python-based HTTP Proxy server uses the wrong boolean operators (CWE-480) causing an incorrect comparison (CWE-697) that identifies an authN failure if all three conditions are met instead of only one, allowing bypass of the proxy authentication (CWE-1390)

  • CVE-2022-29965

    Distributed Control System (DCS) uses a deterministic algorithm to generate utility passwords

  • CVE-2022-29959

    Initialization file contains credentials that can be decoded using a "simple string transformation"

  • CVE-2020-8994

    UART interface for AI speaker uses empty password for root shell

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-1390

  • 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-1390

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-1390 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-1390?

This vulnerability occurs when a system's login or identity verification process is too easy to bypass or fool. While it attempts to check who a user claims to be, the checks are insufficient, allowing attackers to impersonate legitimate users.

Wie gravierend ist CWE-1390?

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-1390 betroffen?

MITRE lists the following affected platforms: ICS/OT, Not Technology-Specific.

Wie kann ich CWE-1390 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-1390?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-1390 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-1390?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/1390.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-1390

CWE-287 Parent

Improper Authentication

Improper Authentication occurs when a system fails to properly verify a user's claimed identity, allowing access without sufficient proof…

CWE-290 Sibling

Authentication Bypass by Spoofing

This weakness occurs when an application's authentication system can be tricked into accepting forged or manipulated credentials, allowing…

CWE-294 Sibling

Authentication Bypass by Capture-replay

This vulnerability occurs when an attacker can intercept and record legitimate authentication traffic, then replay it later to gain…

CWE-295 Sibling

Improper Certificate Validation

This vulnerability occurs when an application fails to properly verify the authenticity of a digital certificate, or performs the…

CWE-306 Sibling

Missing Authentication for Critical Function

This vulnerability occurs when a software feature that performs a sensitive action or uses significant system resources does not verify…

CWE-307 Sibling

Improper Restriction of Excessive Authentication Attempts

This vulnerability occurs when an application fails to properly limit how many times someone can attempt to log in or verify their…

CWE-521 Sibling

Weak Password Requirements

This vulnerability occurs when an application fails to enforce strong password policies, making user accounts easier to compromise through…

CWE-522 Sibling

Insufficiently Protected Credentials

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

CWE-640 Sibling

Weak Password Recovery Mechanism for Forgotten Password

This vulnerability occurs when an application's password reset or recovery feature is poorly designed or implemented, allowing attackers…

Ressourcen

Further reading

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