CVE-2012-2096 in Fivestar Module For Drupal
Summary
by MITRE
The Fivestar module 6.x-1.x before 6.x-1.20 for Drupal does not properly validate voting data, which allows remote attackers to manipulate voting averages via a negative value in the vote parameter.
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Analysis
by VulDB Data Team • 01/26/2018
The CVE-2012-2096 vulnerability affects the Fivestar module version 6.x-1.x before 6.x-1.20 in Drupal content management systems, representing a critical security flaw in the module's input validation mechanisms. This vulnerability specifically targets the voting system functionality that allows users to rate content through star-based reviews, creating a pathway for malicious actors to manipulate the average rating calculations through improper data handling. The issue stems from the module's failure to properly sanitize and validate voting parameters, particularly when negative values are submitted through the vote parameter.
The technical flaw manifests in the module's inability to properly validate user input during the voting process, allowing attackers to submit negative numerical values that can skew the overall average rating calculation. This represents a classic input validation vulnerability that falls under the CWE-20 category of "Improper Input Validation," where the system fails to adequately check or sanitize user-provided data before processing it. The vulnerability enables attackers to manipulate the voting system by submitting malicious vote values that, when aggregated with legitimate votes, produce incorrect average ratings that misrepresent content quality or popularity.
From an operational perspective, this vulnerability poses significant risks to content management systems that rely on user ratings for decision-making processes, reputation management, or content prioritization. Attackers can exploit this flaw to artificially inflate or deflate content ratings, potentially affecting content visibility, user trust, and business decisions based on false data. The impact extends beyond simple rating manipulation as it can be leveraged to influence search engine optimization rankings, affect user engagement metrics, and compromise the integrity of user-generated content evaluation systems. This vulnerability particularly affects Drupal installations using the Fivestar module for implementing rating systems, making it a widespread concern across numerous websites and web applications.
The exploitation of this vulnerability aligns with ATT&CK technique T1566.001 "Phishing" and T1499.004 "Resource Hijacking" by enabling attackers to manipulate system data to achieve their objectives. Organizations should implement immediate mitigations including updating to Fivestar module version 6.x-1.20 or later, which contains proper input validation fixes, and implementing additional security measures such as rate limiting for voting operations, input sanitization at multiple layers, and monitoring for unusual voting patterns. Security administrators should also consider implementing web application firewalls to detect and block suspicious voting parameter submissions, along with regular security audits of third-party modules to ensure proper validation and sanitization of user inputs. The vulnerability demonstrates the critical importance of proper input validation in web applications and serves as a reminder of the potential impact that seemingly minor validation flaws can have on system integrity and user trust.