CVE-2016-3144 in Block Class Module
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Block Class module 7.x-2.x before 7.x-2.2 for Drupal allows remote authenticated users with the "Administer block classes" permission to inject arbitrary web script or HTML via a class name.
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Analysis
by VulDB Data Team • 10/09/2024
The CVE-2016-3144 vulnerability represents a critical cross-site scripting flaw within the Block Class module for Drupal 7.x-2.x versions prior to 2.2. This vulnerability specifically targets the administrative functionality of Drupal websites, where authenticated users with the "Administer block classes" permission can exploit the flaw to inject malicious scripts into the system. The vulnerability stems from insufficient input validation and sanitization of class names used in the block class management interface, creating an avenue for persistent XSS attacks that can affect other users of the administrative interface.
The technical exploitation of this vulnerability occurs through the manipulation of class names within the Block Class module's administrative forms. When administrators create or modify block classes, the module fails to properly sanitize user-supplied class names before rendering them in the web interface. This allows an attacker with the required permissions to input malicious script code within the class name field, which then gets executed in the browsers of other administrators who view the affected administrative pages. The vulnerability is particularly concerning because it requires only authenticated access with specific permissions rather than full administrative privileges, making it more accessible to potential attackers within compromised environments.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to escalate their privileges and compromise the entire Drupal installation. Once an attacker successfully injects malicious code, they can potentially steal session cookies, redirect users to malicious sites, or execute commands on behalf of other administrators. This type of vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications, and it maps to ATT&CK technique T1059.007 for scripting languages and T1566.001 for malicious file execution through web interfaces. The attack vector typically involves the attacker logging into the Drupal system with the "Administer block classes" permission and then crafting malicious class names that contain javascript payloads or html injection code.
Mitigation strategies for CVE-2016-3144 primarily focus on immediate patching of the affected module to version 7.x-2.2 or later, which includes proper input sanitization and validation of class names. Organizations should also implement principle of least privilege by restricting the "Administer block classes" permission to only essential administrators and conducting regular security audits of module configurations. Additional protective measures include implementing content security policies to prevent script execution, monitoring administrative interfaces for suspicious activity, and ensuring that all Drupal core and contributed modules are kept up to date with the latest security patches. Security teams should also consider implementing web application firewalls to detect and block suspicious input patterns that could indicate XSS attempts, while maintaining comprehensive logging of administrative activities to detect potential exploitation attempts.