CVE-2012-1657 in Block Class
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in block_class.module in the Block Class module before 7.x-1.1 for Drupal allows remote authenticated users with certain permissions to inject arbitrary web script or HTML via the class name.
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Analysis
by VulDB Data Team • 12/14/2021
The CVE-2012-1657 vulnerability represents a critical cross-site scripting flaw within the Block Class module for Drupal platforms, specifically affecting versions prior to 7.x-1.1. This vulnerability resides in the block_class.module component and creates a significant security risk for Drupal websites that utilize this module. The flaw enables remote authenticated users to execute malicious scripts within the context of other users' browsers, potentially leading to session hijacking, data theft, or unauthorized actions on behalf of victims. The vulnerability is particularly concerning because it requires only authenticated access with specific permissions, making it exploitable by users who already have some level of access to the system.
The technical implementation of this vulnerability stems from insufficient input validation and output sanitization within the Block Class module's handling of class names. When administrators or users with appropriate permissions create or modify block elements, the module fails to properly sanitize the class name parameters before rendering them in web pages. This lack of proper sanitization allows malicious actors to inject arbitrary HTML and JavaScript code through the class name field, which then executes when other users view the affected pages. The vulnerability specifically targets the module's inability to distinguish between legitimate class names and malicious script injections, creating an XSS vector that can be exploited across the entire Drupal site.
The operational impact of CVE-2012-1657 extends beyond simple script injection, as it can be leveraged for more sophisticated attacks within the Drupal environment. An attacker with the required permissions can craft malicious class names that, when rendered in web browsers, can steal session cookies, redirect users to malicious sites, or even perform administrative actions on behalf of the victim. This vulnerability particularly affects Drupal installations where users with block management permissions exist, as these individuals can create or modify blocks that will be executed by other users. The attack vector is particularly dangerous because it operates within the legitimate administrative interface, making detection more challenging and allowing the attacker to blend in with normal administrative activities.
Organizations affected by this vulnerability should prioritize immediate remediation through updating to Block Class module version 7.x-1.1 or later, which contains the necessary patches to address the XSS flaw. Additionally, implementing proper input validation and output encoding measures within the Drupal installation can provide additional defense-in-depth layers. Security practitioners should review user permissions and ensure that only trusted administrators have access to block management functionality, as this reduces the attack surface for exploitation. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and can be mapped to ATT&CK technique T1059.007 for script injection, demonstrating how this vulnerability fits within broader cybersecurity frameworks and threat modeling approaches.
This vulnerability highlights the critical importance of proper input sanitization and output encoding in web applications, particularly within content management systems where administrative users can influence rendered content. The flaw demonstrates how seemingly minor security oversights in module development can create significant risks for entire web platforms. Organizations should implement comprehensive security testing procedures including automated scanning and manual code reviews to identify similar vulnerabilities in their Drupal installations. Regular security updates and patch management processes become essential defensive measures against such vulnerabilities, as they prevent exploitation of known flaws that attackers can readily leverage. The incident also underscores the need for security awareness training for administrators who work with content management systems, ensuring they understand the potential risks associated with various administrative functions and the importance of maintaining secure configuration practices.