CVE-2016-3169 in Drupal
Summary
by MITRE
The User module in Drupal 6.x before 6.38 and 7.x before 7.43 allows remote attackers to gain privileges by leveraging contributed or custom code that calls the user_save function with an explicit category and loads all roles into the array.
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Analysis
by VulDB Data Team • 10/05/2018
The vulnerability identified as CVE-2016-3169 represents a critical privilege escalation flaw within the Drupal content management system that affects versions prior to 6.38 and 7.43. This issue resides within the User module and demonstrates how improper input validation can lead to severe security implications. The vulnerability specifically targets the user_save function which is commonly utilized by contributed and custom modules within the Drupal ecosystem. When this function is invoked with explicit category parameters, it inadvertently loads all available roles into an array without proper access controls or validation mechanisms.
The technical exploitation of this vulnerability occurs through the manipulation of the user_save function's parameters, where attackers can leverage contributed or custom modules that make direct calls to this function. The flaw stems from the lack of proper role validation during the user saving process, allowing malicious actors to potentially assign administrative privileges to regular user accounts. This occurs because the system fails to properly sanitize or validate the category parameter that gets passed to user_save, enabling unauthorized privilege elevation through crafted input. The vulnerability is particularly dangerous as it can be exploited by remote attackers without requiring authentication, making it an attractive target for automated attacks.
From an operational impact perspective, this vulnerability creates a significant risk for Drupal installations as it allows attackers to gain elevated privileges without proper authentication. The exploitation process can result in full administrative control over affected systems, potentially leading to complete compromise of the web application and underlying infrastructure. Organizations running vulnerable Drupal versions face substantial risk of data breaches, unauthorized content modification, and potential use as a foothold for further attacks within their network environment. The vulnerability also impacts the integrity of user management systems and can lead to unauthorized access to sensitive information stored within the Drupal database.
Security mitigations for CVE-2016-3169 primarily involve immediate patching of affected Drupal installations to the recommended versions 6.38 and 7.43, which contain the necessary fixes to prevent the privilege escalation. Organizations should also implement thorough code review processes to identify and remediate any custom modules that may be making unsafe calls to the user_save function. Network-level protections such as web application firewalls and intrusion detection systems can provide additional defense-in-depth measures. The vulnerability aligns with CWE-20, which describes improper input validation, and maps to ATT&CK technique T1078 for valid accounts and privilege escalation. Regular security assessments and maintaining updated security patches are essential practices to prevent exploitation of similar vulnerabilities in the Drupal ecosystem and other web applications.