CVE-2016-0752 in Ruby on Rails
Summary
by MITRE
Directory traversal vulnerability in Action View in Ruby on Rails before 3.2.22.1, 4.0.x and 4.1.x before 4.1.14.1, 4.2.x before 4.2.5.1, and 5.x before 5.0.0.beta1.1 allows remote attackers to read arbitrary files by leveraging an application's unrestricted use of the render method and providing a .. (dot dot) in a pathname.
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Analysis
by VulDB Data Team • 04/23/2026
The CVE-2016-0752 vulnerability represents a critical directory traversal flaw in Ruby on Rails Action View component that affected multiple versions of the popular web framework. This vulnerability stems from inadequate input validation within the render method implementation, allowing malicious actors to exploit unrestricted pathname handling. The flaw specifically manifests when applications utilize the render method with user-supplied input that contains directory traversal sequences such as .. (dot dot) characters. Attackers can leverage this vulnerability to access arbitrary files on the server filesystem, potentially leading to sensitive data exposure, system compromise, or further exploitation opportunities.
The technical nature of this vulnerability aligns with CWE-22, which defines improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The vulnerability exists at the application layer where the render method fails to properly sanitize or validate file paths before processing them. When user input containing .. sequences is passed to the render method, the framework does not adequately restrict the file system access, allowing attackers to navigate beyond the intended directory boundaries. This weakness specifically impacts the Action View component of Ruby on Rails, which handles view rendering and template processing, making it a fundamental component of web application security.
The operational impact of CVE-2016-0752 is severe and multifaceted, potentially exposing sensitive system information including configuration files, database credentials, application source code, and other confidential data. Attackers can exploit this vulnerability to read files that should normally be restricted, such as password files, SSL certificates, application secrets, and system configuration details. The vulnerability affects multiple Rails versions including 3.2.x, 4.0.x, 4.1.x, 4.2.x, and early 5.x releases, indicating a widespread exposure across the framework's ecosystem. Organizations running affected versions face significant risk of data breaches, compliance violations, and potential system compromise, particularly in environments where applications handle sensitive user or business data.
Mitigation strategies for CVE-2016-0752 primarily involve immediate patching of affected Ruby on Rails installations to the latest secure versions. Organizations should upgrade to Rails 3.2.22.1, 4.1.14.1, 4.2.5.1, or 5.0.0.beta1.1 respectively, depending on their current version. Additionally, implementing input validation and sanitization measures can provide defense-in-depth protection, though patching remains the primary recommendation. Security teams should conduct comprehensive vulnerability assessments to identify applications running affected Rails versions and ensure all instances are updated. The vulnerability also highlights the importance of following secure coding practices and implementing proper access controls when handling user input in web applications. Organizations should consider implementing web application firewalls and monitoring for suspicious file access patterns to detect potential exploitation attempts. This vulnerability serves as a reminder of the critical importance of keeping web frameworks updated and maintaining robust security practices throughout the application lifecycle.