CVE-2015-4375 in Chaos Tool Suite
Summary
by MITRE
The Chaos tool suite (ctools) module 7.x-1.x before 7.x-1.7 for Drupal allows remote attackers to obtain sensitive node titles via (1) an autocomplete search on custom entities without an access query tag or (2) leveraging knowledge of the ID of an entity.
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Analysis
by VulDB Data Team • 04/07/2019
The Chaos tool suite module for Drupal represents a critical security vulnerability identified as CVE-2015-4375 that affects versions 7.x-1.x prior to 7.x-1.7. This vulnerability manifests through two distinct attack vectors that collectively enable remote adversaries to access sensitive node titles within Drupal environments. The flaw resides in the module's inadequate access control mechanisms when handling autocomplete search functionality for custom entities, creating a significant information disclosure risk that can compromise the confidentiality of sensitive content within affected systems.
The technical implementation of this vulnerability stems from the ctools module's failure to properly enforce access controls during autocomplete operations. When custom entities are queried through autocomplete functionality, the system does not adequately validate whether the requesting user possesses appropriate permissions to access the specific entity data. This weakness creates a direct pathway for attackers to bypass normal access restrictions and retrieve node titles that should otherwise remain protected. The vulnerability specifically impacts the module's handling of access query tags, which are essential components for enforcing proper authorization checks in Drupal's access control system. Without proper access query tag implementation, the module fails to validate user permissions before returning entity data, effectively exposing sensitive information through seemingly benign autocomplete searches.
From an operational perspective, this vulnerability presents a substantial risk to organizations relying on Drupal platforms, particularly those handling sensitive or confidential content. Attackers can exploit this flaw to gather intelligence about the content structure of a website, potentially identifying sensitive node titles, content types, or organizational information that could aid in subsequent attacks. The impact extends beyond simple information disclosure as the leaked node titles may contain sensitive metadata that could be leveraged for targeted phishing attacks, social engineering campaigns, or to map out the organization's content management structure. The vulnerability is particularly concerning because it operates silently without requiring authentication, making it accessible to any remote attacker who can interact with the Drupal site's autocomplete functionality.
The attack vectors for this vulnerability align with common exploitation patterns documented in cybersecurity frameworks, particularly those related to information disclosure and privilege escalation. The first vector involves crafting autocomplete search requests against custom entities that lack proper access query tags, while the second leverages knowledge of entity IDs to directly access protected content. Both approaches fall under the broader category of unauthorized information access as defined by CWE-200, which specifically addresses information exposure through improper access control mechanisms. Organizations affected by this vulnerability should consider implementing immediate mitigations including updating to ctools version 7.x-1.7 or later, reviewing and implementing proper access query tags for custom entities, and conducting comprehensive security audits of their Drupal installations to identify other potential access control weaknesses.
Mitigation strategies for CVE-2015-4375 should prioritize the immediate deployment of the patched ctools module version 7.x-1.7, which addresses the core access control implementation issues. Security administrators should also implement additional protective measures such as restricting access to autocomplete endpoints through firewall rules, implementing rate limiting to prevent automated enumeration attacks, and establishing proper monitoring for unusual autocomplete search patterns. The vulnerability's classification under ATT&CK framework's information gathering techniques highlights the importance of comprehensive security monitoring and incident response procedures. Organizations should also review their overall Drupal security posture, ensuring that all contributed modules properly implement access control mechanisms and that custom code follows established security best practices for authorization checks. Regular security assessments and vulnerability scanning should be conducted to identify similar access control weaknesses in other modules or custom implementations that could present analogous security risks.