CVE-2015-3391 in Path Breadcrumbs Module
Summary
by MITRE
The Path Breadcrumbs module before 7.x-3.2 for Drupal allows remote attackers to bypass intended access restrictions and obtaining sensitive node titles by reading a 403 Not Found page.
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Analysis
by VulDB Data Team • 03/19/2019
The Path Breadcrumbs module for Drupal versions prior to 7.x-3.2 contained a critical access control vulnerability that allowed remote attackers to bypass intended security restrictions. This vulnerability specifically affected the module's handling of node access permissions within the breadcrumb navigation system, creating an avenue for unauthorized information disclosure. The flaw manifested when users attempted to access nodes they should not have been permitted to view, yet the module failed to properly enforce access controls during breadcrumb generation processes.
The technical implementation of this vulnerability stemmed from insufficient input validation and access control checks within the module's path resolution logic. When Drupal generated breadcrumb trails for nodes, the system did not adequately verify whether the requesting user possessed proper permissions to access the target node. This weakness allowed attackers to craft specific requests that would trigger the display of node titles and other sensitive information through the 403 Not Found page mechanism, effectively bypassing the intended access restrictions. The vulnerability was particularly concerning because it leveraged the legitimate breadcrumb functionality to expose information that should have remained protected.
The operational impact of this vulnerability extended beyond simple information disclosure, as it enabled attackers to gather intelligence about the system's content structure and potentially identify sensitive nodes within the Drupal installation. Remote attackers could systematically probe the system to discover node titles and access patterns, which could aid in planning more sophisticated attacks. The vulnerability also compromised the principle of least privilege, as users could access content they should not have been authorized to view, potentially exposing confidential information, internal project details, or sensitive business data that was not intended for public consumption.
Organizations running affected Drupal installations faced significant security risks, as this vulnerability could be exploited without requiring authentication credentials or specialized tools. The exploitation process was straightforward, allowing even relatively unsophisticated attackers to discover sensitive node information through standard web browsing techniques. Security professionals recommended immediate patching of the Path Breadcrumbs module to version 7.x-3.2 or later, which contained the necessary access control fixes. Additionally, administrators should review their Drupal module configurations and implement proper access control policies to prevent similar vulnerabilities in other components. This vulnerability aligns with CWE-284, which addresses improper access control, and represents a clear violation of the principle of least privilege that is fundamental to secure system design. The incident highlighted the importance of thorough security testing for contributed modules in open source content management systems, as third-party extensions can introduce significant security risks when not properly vetted.