CVE-2012-2660 in Ruby on Rails
Summary
by MITRE
actionpack/lib/action_dispatch/http/request.rb in Ruby on Rails before 3.0.13, 3.1.x before 3.1.5, and 3.2.x before 3.2.4 does not properly consider differences in parameter handling between the Active Record component and the Rack interface, which allows remote attackers to bypass intended database-query restrictions and perform NULL checks via a crafted request, as demonstrated by certain "[nil]" values, a related issue to CVE-2012-2694.
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Analysis
by VulDB Data Team • 12/05/2021
The vulnerability identified as CVE-2012-2660 represents a critical parameter handling inconsistency within the Ruby on Rails framework that affects multiple version branches including 3.0.x before 3.0.13, 3.1.x before 3.1.5, and 3.2.x before 3.2.4. This flaw stems from a fundamental mismatch in how the Active Record component processes parameters compared to the Rack interface, creating a dangerous gap in the framework's security model. The issue specifically manifests when processing certain parameter values, particularly those containing "[nil]" constructs that are interpreted differently by the database query layer versus the HTTP request parsing layer.
The technical flaw exploits a discrepancy in parameter normalization between Rails' internal components and the underlying Rack middleware interface. When a malicious actor crafts a request containing parameter values that evaluate to nil in the Active Record context but retain their structure in the Rack interface, the framework fails to properly sanitize or validate these inputs. This inconsistency allows attackers to bypass intended database query restrictions that would normally prevent certain types of queries or null checks. The vulnerability specifically targets the handling of array parameters where nil values are present, enabling attackers to manipulate database queries in ways that were not intended by the application's security controls.
The operational impact of this vulnerability is severe as it enables remote attackers to perform unauthorized database operations that could lead to data exposure, data manipulation, or even complete system compromise depending on the application's database permissions. Attackers can exploit this weakness to bypass access controls that rely on parameter validation, potentially allowing them to perform NULL checks or other database operations that should have been restricted. The vulnerability is particularly dangerous because it operates at the framework level, meaning that applications built on affected Rails versions are automatically susceptible to this attack vector regardless of the specific application logic implemented by developers.
This vulnerability aligns with CWE-20, "Improper Input Validation," and represents a classic case of inconsistent data handling between different layers of a software system. The attack pattern described in the MITRE ATT&CK framework would fall under the T1071.004 technique for application layer protocol, specifically targeting web application frameworks. The flaw demonstrates how seemingly minor inconsistencies in parameter processing can create significant security implications, particularly when dealing with database interactions that are fundamental to most web applications. Organizations using affected Rails versions should prioritize immediate patching to address this vulnerability, as the attack surface extends to any application that processes user-supplied parameters through the Rails framework's parameter handling mechanisms. The vulnerability also highlights the importance of thorough testing across different framework components to ensure consistent behavior and prevent security gaps that can be exploited by attackers.