CVE-2016-3164 in Drupal
Summary
by MITRE
Drupal 6.x before 6.38, 7.x before 7.43, and 8.x before 8.0.4 might allow remote attackers to conduct open redirect attacks by leveraging (1) custom code or (2) a form shown on a 404 error page, related to path manipulation.
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Analysis
by VulDB Data Team • 07/24/2022
This vulnerability affects multiple versions of the Drupal content management system and represents a significant security flaw that enables attackers to perform open redirect attacks. The issue stems from inadequate input validation and path manipulation handling within the application's routing mechanisms. Attackers can exploit this weakness to redirect users to malicious websites by manipulating URL paths, potentially leading to phishing attacks or credential theft. The vulnerability impacts Drupal 6.x systems before version 6.38, 7.x systems before version 7.43, and 8.x systems before version 8.0.4, making it a widespread concern across major Drupal versions. This type of vulnerability falls under the CWE-601 Open Redirect weakness category, which is classified as a critical security risk in the CWE top 25 most dangerous software weaknesses list. The attack vector specifically leverages two primary methods: custom code injection that can be executed within the Drupal environment and exploitation of forms displayed on 404 error pages, which are commonly accessible and often lack proper security controls.
The technical implementation of this vulnerability involves the manipulation of URL paths that are not properly sanitized or validated before being used for redirection purposes. When Drupal processes user requests, it handles path information that may contain malicious redirection targets. The flaw occurs because the system does not adequately verify that redirect destinations are legitimate and within the expected domain boundaries. This allows attackers to craft URLs that appear to lead to legitimate Drupal pages but actually redirect users to external malicious sites. The 404 error page form exploitation aspect is particularly concerning because these pages are often less secured than main application pages and may not implement the same input validation measures. The vulnerability demonstrates a failure in the principle of least privilege and proper input sanitization, allowing attackers to bypass normal access controls through path manipulation techniques.
The operational impact of CVE-2016-3164 extends beyond simple redirection attacks, as it can be leveraged for more sophisticated social engineering campaigns. Attackers can use this vulnerability to create convincing phishing pages that appear to be legitimate Drupal administrative interfaces or user account pages. The open redirect capability provides attackers with a method to bypass security measures that might otherwise prevent direct access to malicious content. This vulnerability is particularly dangerous in environments where users frequently interact with Drupal sites and may not be trained to recognize suspicious redirects. Organizations using affected Drupal versions face potential data breaches, credential theft, and reputational damage when attackers successfully exploit this weakness. The vulnerability also increases the risk of cross-site scripting attacks when combined with other security flaws, as attackers can use the redirect capability to deliver malicious payloads through carefully crafted URLs.
Organizations should immediately upgrade to patched versions of Drupal to address this vulnerability, with Drupal 6.38, 7.43, and 8.0.4 being the minimum recommended versions. Security teams should implement additional monitoring for suspicious redirect patterns and conduct regular security audits of all Drupal installations. Input validation should be strengthened at all levels of the application, particularly for URL parameters and path information. The use of web application firewalls and security headers can provide additional protection layers against exploitation attempts. Organizations should also implement proper access controls and ensure that 404 error pages do not contain forms or functionality that could be exploited. This vulnerability aligns with ATT&CK technique T1566.001 for phishing and T1071.004 for application layer protocols, demonstrating how path manipulation can be used as part of broader attack chains. Regular security training for administrators and developers is essential to prevent exploitation through custom code injection methods, as this requires understanding of Drupal's security model and proper coding practices.