CVE-2016-9449 in Drupal
Summary
by MITRE
The taxonomy module in Drupal 7.x before 7.52 and 8.x before 8.2.3 might allow remote authenticated users to obtain sensitive information about taxonomy terms by leveraging inconsistent naming of access query tags.
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Analysis
by VulDB Data Team • 10/04/2022
The vulnerability identified as CVE-2016-9449 affects the taxonomy module in Drupal versions 7.x prior to 7.52 and 8.x prior to 8.2.3, representing a significant information disclosure weakness that impacts the core content management system's access control mechanisms. This issue stems from inconsistent naming practices within access query tags that are used to manage permissions for taxonomy terms, creating a scenario where authenticated users can potentially bypass intended access restrictions and gain unauthorized visibility into taxonomy data they should not be able to access. The vulnerability specifically exploits the way Drupal handles access control queries for taxonomy terms, where the inconsistent naming of query tags allows malicious users to craft requests that can reveal information about taxonomy terms they do not have explicit permissions to view.
The technical flaw manifests through improper handling of access control query tags within the taxonomy module's database query construction process. When Drupal processes requests for taxonomy term information, it constructs database queries with specific access control tags that should enforce permission boundaries. However, the inconsistent naming of these tags creates a situation where authenticated users can manipulate their requests to access taxonomy data that should be restricted based on their role permissions. This vulnerability operates at the intersection of database access control and query building mechanisms, where the improper tagging system fails to maintain consistent access boundaries that would normally be enforced by Drupal's permission system.
The operational impact of this vulnerability extends beyond simple information disclosure, as it represents a serious degradation of the security model within Drupal's taxonomy management system. An authenticated user who can exploit this vulnerability can potentially access taxonomy terms that contain sensitive information, including but not limited to content categorization data, user-specific term relationships, or organizational structure information that is typically restricted to specific user roles. This could lead to unauthorized data exposure that might reveal internal organizational structures, content relationships, or other sensitive metadata that should remain confidential within the system. The vulnerability particularly affects environments where taxonomy terms contain classified information or where access to certain content categories should be strictly controlled based on user roles and permissions.
Organizations affected by this vulnerability should immediately upgrade to Drupal 7.52 or 8.2.3, which contain the necessary patches to address the inconsistent naming issue in access query tags. The fix implemented in these versions ensures that access control query tags maintain consistent naming conventions that properly enforce the intended access boundaries for taxonomy terms. Security administrators should also conduct thorough access control reviews to identify any potential exploitation that may have occurred before the patch was applied, particularly focusing on taxonomy term access logs and user activity patterns that might indicate unauthorized access attempts. Additionally, organizations should implement monitoring for unusual taxonomy term access patterns that could indicate exploitation attempts, as the vulnerability requires authenticated users but does not require elevated privileges beyond normal user accounts.
This vulnerability aligns with CWE-200, which addresses "Information Exposure," and represents a specific instance where access control mechanisms fail to properly enforce information flow restrictions. The issue also relates to ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation," as users can potentially leverage this vulnerability to gain access to information that should be restricted, effectively expanding their effective access privileges through information disclosure. The inconsistency in query tag naming creates an access control bypass that violates fundamental security principles, particularly the principle of least privilege, where users should only have access to information necessary for their specific roles within the system.