CVE-2012-3463 in Ruby on Rails
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in actionpack/lib/action_view/helpers/form_tag_helper.rb in Ruby on Rails 3.x before 3.0.17, 3.1.x before 3.1.8, and 3.2.x before 3.2.8 allows remote attackers to inject arbitrary web script or HTML via the prompt field to the select_tag helper.
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Analysis
by VulDB Data Team • 03/27/2021
The vulnerability described in CVE-2012-3463 represents a critical cross-site scripting flaw within the Ruby on Rails web application framework that affects multiple version streams including 3.0.x, 3.1.x, and 3.2.x series. This vulnerability specifically targets the form_tag_helper component within the actionview library, which is fundamental to Rails applications that generate HTML forms and user interface elements. The flaw resides in how the framework handles user input when rendering select tag elements, creating a pathway for malicious actors to inject arbitrary JavaScript code or HTML content into web pages viewed by other users. The vulnerability's impact extends across numerous Rails applications that utilize the select_tag helper function, making it particularly dangerous given Rails' widespread adoption in web development.
The technical mechanism of exploitation involves the prompt field parameter within the select_tag helper method, which fails to properly sanitize or escape user-provided input before rendering it into HTML output. When an attacker provides malicious input containing script tags or other HTML constructs in the prompt field, the Rails framework processes this input without adequate validation, allowing the malicious code to execute within the context of other users' browsers. This behavior aligns with CWE-79, which defines cross-site scripting vulnerabilities as weaknesses that occur when an application incorporates untrusted data into web pages without proper validation or escaping, and specifically maps to the category of "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')" within the CWE taxonomy. The vulnerability demonstrates how input validation failures in web framework components can lead to widespread security compromise across applications built on that framework.
The operational impact of this vulnerability is severe and multifaceted, as it enables attackers to execute arbitrary code in victims' browsers, potentially leading to session hijacking, credential theft, data exfiltration, and other malicious activities. Attackers can craft malicious payloads that exploit this vulnerability through various vectors including web forms, URL parameters, or API endpoints that utilize the affected select_tag helper. The vulnerability's persistence across multiple Rails versions means that applications using any of the affected versions remain at risk, requiring immediate patching to mitigate potential exploitation. This vulnerability also aligns with several ATT&CK techniques including T1059.007 for Scripting and T1566.001 for Phishing, as attackers can leverage this flaw to deliver malicious payloads through compromised web forms or crafted user interactions. The widespread nature of Ruby on Rails applications means that successful exploitation could affect numerous websites and services simultaneously.
Mitigation strategies for CVE-2012-3463 require immediate implementation of security patches to upgrade affected Rails versions to the patched releases, specifically 3.0.17, 3.1.8, and 3.2.8 respectively. Organizations should also implement comprehensive input validation and output escaping mechanisms as defensive measures, ensuring that all user-provided data is properly sanitized before being rendered in web pages. Additional protective measures include implementing Content Security Policy headers to limit script execution, conducting regular security audits of web applications, and establishing proper security monitoring to detect potential exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date dependencies and following secure coding practices within web frameworks, particularly regarding user input handling and HTML output generation. Security teams should prioritize patching affected applications immediately while also reviewing their application code for similar input handling patterns that might be susceptible to similar vulnerabilities. The incident serves as a reminder of how framework-level vulnerabilities can have cascading effects across thousands of applications, emphasizing the critical need for robust security practices in web development environments.