CVE-2013-6385 in Drupal
Summary
by MITRE
The form API in Drupal 6.x before 6.29 and 7.x before 7.24, when used with unspecified third-party modules, performs form validation even when CSRF validation has failed, which might allow remote attackers to trigger application-specific impacts such as arbitrary code execution via application-specific vectors.
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Analysis
by VulDB Data Team • 06/02/2021
The vulnerability identified as CVE-2013-6385 represents a critical security flaw in the Drupal content management system's form API implementation across multiple versions. This issue specifically affects Drupal 6.x versions prior to 6.29 and Drupal 7.x versions prior to 7.24, where the system's security mechanisms fail to properly enforce cross-site request forgery validation. The vulnerability arises from the improper execution flow within the form validation process, where the system continues to process form submissions even when CSRF protection measures have been bypassed or failed.
The technical nature of this flaw stems from a breakdown in the security architecture's defensive layers, where the form API's validation logic does not adequately check for CSRF token authenticity before proceeding with subsequent validation steps. This creates a dangerous condition where malicious actors can craft specially crafted requests that bypass the initial CSRF protection mechanisms while still triggering the form processing pipeline. The vulnerability is particularly concerning because it operates at a fundamental level of the application's security framework, affecting how the system validates user input and handles authentication tokens.
From an operational perspective, this vulnerability exposes Drupal installations to significant risk of exploitation, particularly when third-party modules are present that interact with the form API. The impact can range from unauthorized administrative actions to full system compromise, depending on the specific application configuration and the presence of vulnerable modules. Attackers can leverage this weakness to execute arbitrary code on the target system, potentially gaining complete control over the web server and accessing sensitive data or modifying content. The vulnerability's exploitation requires minimal privileges and can be automated, making it particularly dangerous in large-scale deployments.
The security implications extend beyond simple privilege escalation, as this flaw can be combined with other vulnerabilities to create more sophisticated attack vectors. According to CWE classification, this represents a weakness in the form of inadequate input validation and improper error handling within security-critical components. The vulnerability aligns with ATT&CK techniques related to privilege escalation and code execution, as it allows attackers to bypass security controls and execute malicious payloads. Organizations using affected Drupal versions should immediately implement patches, as the vulnerability can be exploited remotely without authentication. Additionally, implementing additional security measures such as web application firewalls, monitoring for suspicious form submissions, and regular security audits can help mitigate the risk until full patching is completed.
The vulnerability demonstrates the critical importance of proper security architecture design and the necessity of maintaining up-to-date software components. Third-party modules often introduce additional attack surfaces that can amplify existing vulnerabilities, highlighting the need for comprehensive security assessments during system configuration. Organizations should prioritize immediate patch deployment and consider implementing security monitoring solutions to detect potential exploitation attempts. The incident underscores the importance of following security best practices, including regular security updates, proper input validation, and maintaining awareness of security advisories from software vendors.