CVE-2007-3227 in Ruby on Rails
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the to_json (ActiveRecord::Base#to_json) function in Ruby on Rails before edge 9606 allows remote attackers to inject arbitrary web script via the input values.
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Analysis
by VulDB Data Team • 01/17/2025
The vulnerability described in CVE-2007-3227 represents a critical cross-site scripting flaw within the Ruby on Rails web application framework, specifically affecting the to_json method implementation in ActiveRecord::Base. This vulnerability exists in versions prior to edge 9606 and allows remote attackers to execute malicious web scripts through input values that are processed by the JSON serialization function. The flaw stems from insufficient sanitization of user-provided data during the conversion process from ruby objects to JSON format, creating an avenue for attackers to inject malicious scripts that can execute in the context of other users' browsers.
The technical implementation of this vulnerability occurs when the to_json method processes input values without proper escaping or sanitization of special characters that could be interpreted as HTML or JavaScript code. When user-supplied data containing script tags or other malicious payloads is included in objects that are serialized to JSON format, the resulting output can contain executable code that gets interpreted by web browsers when rendered. This particular flaw affects the ActiveRecord::Base#to_json function which is commonly used throughout Rails applications for API responses and data exchange operations, making it a widespread potential attack vector across numerous applications built on this framework. The vulnerability is classified as a classic XSS issue under CWE-79, which specifically addresses the improper neutralization of input during web page generation, and aligns with ATT&CK technique T1566.001 for initial access through malicious web content.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform session hijacking, deface web applications, steal sensitive user data, or redirect users to malicious sites. Since Rails applications commonly expose data through JSON APIs, the attack surface is broad and affects various application components including user profiles, content management systems, and administrative interfaces. The vulnerability is particularly dangerous because it can be exploited through multiple vectors including form submissions, API endpoints, and any input field that gets serialized to JSON format. Attackers can craft malicious payloads that, when processed by the vulnerable to_json method, will execute in the browser context of unsuspecting users who view the affected content. This makes the vulnerability particularly effective for mass exploitation across multiple applications and user bases.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to Rails version edge 9606 or later, which contains the necessary patches to sanitize input values properly during JSON serialization. Additional defensive measures include implementing proper input validation and output encoding for all user-provided data, particularly when preparing data for JSON responses. Security teams should also consider implementing Content Security Policy headers to limit script execution capabilities in web browsers, and establish automated testing procedures to detect similar vulnerabilities in custom application code. The vulnerability demonstrates the importance of proper data sanitization in web frameworks and highlights how seemingly innocuous methods like JSON serialization can become attack vectors when input validation is insufficient, making it a critical lesson for application security practitioners in maintaining secure coding practices throughout the development lifecycle.