CVE-2014-9016 in Drupal
Summary
by MITRE
The password hashing API in Drupal 7.x before 7.34 and the Secure Password Hashes (aka phpass) module 6.x-2.x before 6.x-2.1 for Drupal allows remote attackers to cause a denial of service (CPU and memory consumption) via a crafted request.
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Analysis
by VulDB Data Team • 01/05/2025
The vulnerability identified as CVE-2014-9016 represents a significant denial of service weakness within the Drupal content management platform ecosystem. This flaw specifically targets the password hashing mechanisms that are fundamental to user authentication security. The vulnerability affects Drupal 7.x versions prior to 7.34 and the Secure Password Hashes module for Drupal 6.x versions before 6.x-2.1, creating a critical attack surface where malicious actors can exploit the hashing algorithms to consume excessive system resources. The issue stems from the implementation of the phpass library which is responsible for generating secure password hashes, making it a core component of Drupal's authentication infrastructure.
The technical exploitation of this vulnerability occurs through crafted requests that deliberately trigger resource-intensive password hashing operations. When a malicious user submits specially constructed authentication requests, the system processes these inputs through the vulnerable password hashing functions which are designed to be computationally expensive to prevent brute force attacks. However, the implementation contains a flaw where these expensive operations can be triggered repeatedly without proper rate limiting or input validation, causing the system to consume excessive cpu cycles and memory resources. This creates a scenario where legitimate users cannot access the system as the server becomes overwhelmed with processing these malicious requests, effectively rendering the service unavailable.
The operational impact of CVE-2014-9016 extends beyond simple service disruption to potentially compromise the overall availability and performance of web applications running vulnerable Drupal installations. Attackers can leverage this vulnerability to perform sustained denial of service attacks that gradually exhaust system resources, making it particularly dangerous for high-traffic websites or applications that rely heavily on user authentication. The vulnerability aligns with CWE-400, which catalogs weaknesses related to resource exhaustion, and can be mapped to ATT&CK technique T1499.004, which describes denial of service through resource exhaustion. Organizations running affected Drupal versions face significant risk as attackers can consume server resources without requiring any authentication credentials, making this attack vector particularly effective and difficult to detect.
Mitigation strategies for CVE-2014-9016 primarily involve immediate patching of affected Drupal installations to versions 7.34 or later, along with the corresponding Secure Password Hashes module updates for Drupal 6.x. System administrators should also implement rate limiting mechanisms at the web server level to prevent excessive authentication request processing and monitor for unusual patterns of password hash usage. Network-level protections such as intrusion detection systems can help identify and block malicious requests attempting to exploit this vulnerability. Additionally, organizations should consider implementing application firewalls and web application security controls to detect and prevent the specific patterns associated with this attack. The vulnerability serves as a reminder of the importance of proper input validation and resource management in cryptographic implementations, particularly when dealing with functions that are intentionally computationally expensive to prevent attacks but must also be protected against abuse.