CWE-548: Exposure of Information Through Directory Listing

Definition

What is CWE-548?

This vulnerability occurs when a web server is misconfigured to display a full list of files within a directory instead of serving a default web page, unintentionally exposing sensitive resources to anyone who visits the URL.

Directory listings happen when a web server (like Apache, Nginx, or IIS) can't find a default index file (e.g., index.html) and its configuration allows it to show the folder's contents. This acts as a roadmap for attackers, revealing backup files, configuration scripts, temporary uploads, or administrative interfaces that were never meant to be public. A simple manual check or a DAST scan can easily uncover this issue. Prevention involves configuring your server to disable directory listings and always ensuring a default index page exists. For developers, this means checking server configuration files for directives like 'Options -Indexes' in Apache or 'autoindex off' in Nginx. Managing this at scale across hundreds of services is difficult; an ASPM like Plexicus can help you continuously track and automatically flag these misconfigurations across your entire application portfolio.

Auswirkungen in der Praxis

Real-world CVEs caused by CWE-548

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

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 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-548

Architecture and Design / System Configuration Recommendations include restricting access to important directories or files by adopting a need to know requirement for both the document and server root, and turning off features such as Automatic Directory Listings that could expose private files and provide information that could be utilized by an attacker when formulating or conducting an attack.

Erkennungssignale

How to detect CWE-548

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.)

CWE-548

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-548?

This vulnerability occurs when a web server is misconfigured to display a full list of files within a directory instead of serving a default web page, unintentionally exposing sensitive resources to anyone who visits the URL.

Wie gravierend ist CWE-548?

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-548 betroffen?

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

Wie kann ich CWE-548 verhindern?

Recommendations include restricting access to important directories or files by adopting a need to know requirement for both the document and server root, and turning off features such as Automatic Directory Listings that could expose private files and provide information that could be utilized by an attacker when formulating or conducting an attack.

Wie erkennt und behebt Plexicus CWE-548?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-548 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-548?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/548.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-548

CWE-497 Parent

Exposure of Sensitive System Information to an Unauthorized Control Sphere

This vulnerability occurs when an application unintentionally reveals sensitive details about its underlying system, such as file paths,…

CWE-214 Sibling

Invocation of Process Using Visible Sensitive Information

This vulnerability occurs when a process is started with sensitive data, such as passwords or API keys, passed directly in its…

Ressourcen

Bereit zu validieren, was zählt.

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

Pentest buchen

Exposure of Information Through Directory Listing