CWE-288 Base Incomplete

Authentication Bypass Using an Alternate Path or Channel

This vulnerability occurs when a system has a primary login requirement, but attackers can find an unprotected backdoor or alternative route that completely bypasses those checks.

Definition

What is CWE-288?

This vulnerability occurs when a system has a primary login requirement, but attackers can find an unprotected backdoor or alternative route that completely bypasses those checks.
Think of it like a building with a guarded front door but an unlocked side window. The main application flow correctly validates user credentials, but developers might overlook a secondary API endpoint, a hidden administrative page, a debug interface, or a direct file path that doesn't enforce the same authentication rules. Attackers discover these alternate channels through reconnaissance, fuzzing, or analyzing application structure, allowing them to access restricted functions or data without ever logging in. This often happens during development when temporary access points are created for testing and never removed, or when different system components have inconsistent security policies. To prevent it, you must ensure every single entry point into protected functionality—including APIs, files, and hidden directories—enforces the same robust authentication checks. Regular security audits should map all access paths and verify none provide a secret bypass to your core security gate.
Vulnerability Diagram CWE-288
Auth Bypass via Alternate Path /login password required /internal/api no auth (legacy) Same backend no second check Sensitive data accessible Hardened front door, side door wide open.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-288

  • CVE-2000-1179

    Router allows remote attackers to read system logs without authentication by directly connecting to the login screen and typing certain control characters.

  • CVE-1999-1454

    Attackers with physical access to the machine may bypass the password prompt by pressing the ESC (Escape) key.

  • CVE-1999-1077

    OS allows local attackers to bypass the password protection of idled sessions via the programmer's switch or CMD-PWR keyboard sequence, which brings up a debugger that the attacker can use to disable the lock.

  • CVE-2003-0304

    Direct request of installation file allows attacker to create administrator accounts.

  • CVE-2002-0870

    Attackers may gain additional privileges by directly requesting the web management URL.

  • CVE-2002-0066

    Bypass authentication via direct request to named pipe.

  • CVE-2003-1035

    User can avoid lockouts by using an API instead of the GUI to conduct brute force password guessing.

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 Verilog

Verwundbar Verilog 
assign addr_auth = (address == 32'hF00) ? 1: 0;
Sicheres Codebeispiel

Secure Verilog

The bugged line of code is repeated in the Bad example above. Weakness arises from the fact that the SECURE_ME register can be modified by writing to the shadow register COPY_OF_SECURE_ME, the address of COPY_OF_SECURE_ME should also be included in the check. That buggy line of code should instead be replaced as shown in the Good Code Snippet below.

Sicher Verilog 
assign addr_auth = (address == 32'hF00 || address == 32'h800F00) ? 1: 0;
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-288

  • Architecture and Design Funnel all access through a single choke point to simplify how users can access a resource. For every access, perform a check to determine if the user has permissions to access the resource.
Erkennungssignale

How to detect CWE-288

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-288 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.

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Häufig gestellte Fragen

Frequently asked questions

Was ist CWE-288?

This vulnerability occurs when a system has a primary login requirement, but attackers can find an unprotected backdoor or alternative route that completely bypasses those checks.

Wie gravierend ist CWE-288?

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-288 betroffen?

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

Wie kann ich CWE-288 verhindern?

Funnel all access through a single choke point to simplify how users can access a resource. For every access, perform a check to determine if the user has permissions to access the resource.

Wie erkennt und behebt Plexicus CWE-288?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-288 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-288?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/288.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-288

CWE-306 Parent

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-322 Sibling

Key Exchange without Entity Authentication

This vulnerability occurs when a system establishes a cryptographic key with another party without first confirming that party's true…

CWE-420 Peer

Unprotected Alternate Channel

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

CWE-1299 Child

Missing Protection Mechanism for Alternate Hardware Interface

This vulnerability occurs when a hardware component's security controls only protect the primary access path, leaving alternate interfaces…

CWE-425 Child

Direct Request ('Forced Browsing')

This vulnerability occurs when a web application fails to verify user permissions for every protected page, file, or API endpoint,…

Ressourcen

Further reading

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