CVE-2009-4533 in Webform
Summary
by MITRE
The Webform module 5.x before 5.x-2.8 and 6.x before 6.x-2.8, a module for Drupal, does not prevent caching of a page that contains token placeholders for a default value, which allows remote attackers to read session variables via unspecified vectors.
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Analysis
by VulDB Data Team • 01/26/2019
The vulnerability identified as CVE-2009-4533 affects the Webform module in Drupal versions 5.x before 5.x-2.8 and 6.x before 6.x-2.8, representing a critical security flaw in web application frameworks that has significant implications for data confidentiality and session management. This issue stems from improper handling of token placeholders within web forms, creating a scenario where sensitive session data becomes accessible through cached page responses. The vulnerability is classified under CWE-200, which specifically addresses information exposure, and falls within the broader category of insecure data handling practices that have been consistently documented in security frameworks and standards.
The technical flaw manifests when the Webform module processes forms containing token placeholders that are intended to populate default values for session variables. During the page rendering process, the module fails to properly sanitize or prevent caching of these pages, allowing cached versions to retain session data that should remain confidential. This creates an attack vector where remote adversaries can exploit the caching mechanism to retrieve session variables that contain sensitive user information, authentication tokens, or other private data that should not be accessible through cached page responses. The vulnerability is particularly concerning because it leverages Drupal's built-in caching system to expose data that would normally be protected by session management protocols.
The operational impact of this vulnerability extends beyond simple data exposure, as it represents a fundamental breakdown in the security model of the affected Drupal installations. Attackers can potentially access session variables that contain user credentials, personal information, or other sensitive data that should remain isolated within the session context. This flaw undermines the core principle of session isolation and can lead to unauthorized access to user accounts, data breaches, and potential privilege escalation within affected systems. The vulnerability affects organizations running Drupal websites that utilize the Webform module for user data collection, making it particularly relevant for content management systems that handle sensitive information.
Mitigation strategies for CVE-2009-4533 require immediate patching of affected Drupal installations to versions 5.x-2.8 and 6.x-2.8 or later, which contain the necessary fixes to prevent caching of pages with token placeholders. Organizations should also implement additional security measures such as disabling caching for pages containing sensitive form data, implementing proper access controls, and monitoring for unauthorized access attempts. The vulnerability demonstrates the importance of proper input validation and output sanitization in web applications, aligning with ATT&CK technique T1566 which covers credential access through various attack vectors. Security teams should conduct comprehensive audits of their Drupal installations to identify all instances of the Webform module and ensure proper patching across all affected systems.