CVE-2012-5651 in Drupal
Summary
by MITRE
Drupal 6.x before 6.27 and 7.x before 7.18 displays information for blocked users, which might allow remote attackers to obtain sensitive information by reading the search results.
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Analysis
by VulDB Data Team • 12/21/2021
This vulnerability affects Drupal content management systems version 6.x prior to 6.27 and 7.x prior to 7.18 where blocked user accounts remain accessible through search functionality. The flaw stems from insufficient access controls within the search module implementation, allowing unauthorized remote attackers to retrieve information about blocked users through search result displays. The vulnerability is categorized under CWE-200, which addresses improper exposure of sensitive information, and aligns with ATT&CK technique T1082, focusing on discovery of system information through search capabilities. When users are blocked in Drupal, their accounts typically should be restricted from accessing system resources, but this vulnerability enables search engines and result displays to reveal metadata about these accounts. Attackers can exploit this by performing targeted searches that return results containing information about blocked users, potentially including usernames, email addresses, or other identifying attributes that should normally be restricted. This represents a significant information disclosure risk as it violates fundamental access control principles where blocked users should not be visible through standard system interfaces.
The technical implementation flaw occurs within the search indexing and result rendering components of Drupal's core system. When search functionality processes queries, it fails to properly filter out blocked user records from the results, even though these accounts should be excluded from public visibility. This issue is particularly concerning because Drupal's search module typically indexes content from all users, including those who have been blocked due to security violations or policy breaches. The vulnerability enables attackers to enumerate blocked accounts through search queries, potentially revealing patterns in user behavior, account creation times, or other metadata that could aid in further exploitation attempts. The impact extends beyond simple information disclosure as it can facilitate account enumeration, which is often a precursor to more sophisticated attacks such as credential stuffing or targeted social engineering campaigns.
The operational impact of this vulnerability can be substantial for organizations relying on Drupal for content management and user account handling. Attackers can use this information to build comprehensive user profiles, identify system administrators, or discover accounts that may have been compromised. The vulnerability particularly affects sites with large user bases where blocked accounts are frequently created due to security incidents, spam detection, or policy violations. Organizations may experience reputational damage if sensitive user information becomes exposed through search results, especially when blocked accounts contain personal identifiers or business-related information. The vulnerability also undermines the integrity of the system's access control mechanisms, potentially exposing other related security features that depend on proper user account isolation. Security teams may need to implement emergency patches or workarounds to prevent exploitation while maintaining system availability and functionality.
Mitigation strategies for this vulnerability include immediate deployment of the official Drupal security patches released for versions 6.27 and 7.18, which address the improper access control in search results. Organizations should also implement additional monitoring of search functionality for unusual query patterns that might indicate exploitation attempts. Network segmentation and access controls should be reviewed to limit exposure of search functionality to unauthorized users, particularly in environments where sensitive information is stored. Security configurations should be audited to ensure that blocked user accounts are properly excluded from all search indexes and result displays. Regular security assessments should include testing of access controls and search functionality to prevent similar issues from emerging in other system components. System administrators should also consider implementing additional logging and alerting mechanisms for search queries that return results containing blocked user information, enabling rapid detection of potential exploitation attempts. The vulnerability demonstrates the importance of comprehensive access control testing across all system interfaces and the necessity of maintaining up-to-date security patches as a fundamental defense mechanism against information disclosure attacks.