CVE-2009-3435 in Devel
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the variable editor in the Devel module 5.x before 5.x-1.2 and 6.x before 6.x-1.18, a module for Drupal, allows remote attackers to inject arbitrary web script or HTML via a variable name.
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Analysis
by VulDB Data Team • 01/22/2019
The CVE-2009-3435 vulnerability represents a critical cross-site scripting flaw within the Devel module for Drupal content management systems. This vulnerability specifically affects Drupal versions 5.x prior to 5.x-1.2 and 6.x prior to 6.x-1.18, where the variable editor component fails to properly sanitize user input. The flaw resides in how the module handles variable names submitted through web forms, creating an avenue for malicious actors to execute arbitrary JavaScript code within the context of authenticated users' browsers. The vulnerability operates under the Common Weakness Enumeration classification of CWE-79, which specifically addresses Cross-Site Scripting flaws in software applications.
The technical implementation of this vulnerability allows remote attackers to inject malicious payloads through variable names within the Devel module's administrative interface. When administrators or users with appropriate privileges access the variable editor, the improperly sanitized input gets rendered directly into web pages without adequate output encoding or validation. This creates a persistent XSS vector where attackers can craft variable names containing malicious script tags or HTML content that executes in the browser of any user who views the affected page. The attack requires no special privileges beyond access to the Drupal administrative interface, making it particularly dangerous in environments where multiple users have varying levels of access to module configuration features.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it enables sophisticated attack vectors including session hijacking, credential theft, and the potential for privilege escalation within the Drupal environment. Attackers can exploit this vulnerability to establish persistent backdoors, manipulate user sessions, or redirect victims to malicious sites that appear legitimate within the trusted Drupal domain. The vulnerability affects the core functionality of the Devel module which is commonly used for debugging and development purposes, meaning that organizations with active development environments are particularly at risk. This vulnerability directly maps to ATT&CK technique T1566.001 for credential access through phishing and T1059.001 for command and scripting interpreter execution, as attackers can leverage the XSS to execute malicious commands in the victim's browser context.
Organizations should immediately implement multiple layers of defense against this vulnerability, beginning with the mandatory upgrade to patched versions of the Devel module as specified in the CVE references. The immediate mitigation strategy involves ensuring that all Drupal installations running affected versions of the Devel module are updated to the latest stable releases. Additionally, administrators should implement strict input validation and output encoding practices within their web applications, particularly for any custom modules that handle user-supplied data. Network-level protections such as web application firewalls and content security policies can provide additional defense in depth, though these measures should not replace the fundamental requirement for patch management. The vulnerability also highlights the importance of principle of least privilege in Drupal environments, where administrative access should be restricted to authorized personnel only to minimize the potential impact of such attacks. Regular security audits and vulnerability assessments should include checks for outdated or unpatched modules, as this vulnerability demonstrates the critical need for maintaining up-to-date software components in complex web applications.