CVE-2011-0449 in Ruby on Rails
Summary
by MITRE
actionpack/lib/action_view/template/resolver.rb in Ruby on Rails 3.0.x before 3.0.4, when a case-insensitive filesystem is used, does not properly implement filters associated with the list of available templates, which allows remote attackers to bypass intended access restrictions via an action name that uses an unintended case for alphabetic characters.
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Analysis
by VulDB Data Team • 08/03/2024
The vulnerability described in CVE-2011-0449 represents a critical access control flaw within the Ruby on Rails framework that specifically affects versions 3.0.x prior to 3.0.4. This issue stems from the improper implementation of template resolution mechanisms within the action_view component, particularly when operating on filesystems that do not distinguish between uppercase and lowercase characters. The flaw creates a scenario where attackers can manipulate template access by leveraging case variations in action names, effectively bypassing the intended security restrictions that govern template availability and access permissions.
The technical implementation of this vulnerability resides in the actionpack/lib/action_view/template/resolver.rb file where the template resolution process fails to properly apply filters when enumerating available templates. When a case-insensitive filesystem is in use, the system does not correctly validate or sanitize the case sensitivity of action names during template lookup operations. This allows malicious actors to construct requests using unconventional capitalization patterns that can access templates which should otherwise be restricted or unavailable to unauthorized users. The vulnerability specifically exploits the difference between how the system processes template names internally versus how it validates access controls based on those names.
From an operational perspective, this vulnerability poses significant risks to web applications built on Ruby on Rails 3.0.x frameworks. Attackers can potentially access sensitive templates, view restricted content, or gain unauthorized access to application functionality that should be protected. The impact extends beyond simple information disclosure, as it can enable further exploitation by allowing attackers to discover internal application structure, access administrative templates, or potentially escalate privileges within the application. The vulnerability is particularly dangerous because it can be exploited without requiring authentication credentials, making it a severe threat to application security.
The root cause of this vulnerability aligns with CWE-284, which addresses improper access control mechanisms, and can be mapped to ATT&CK technique T1213.002 for data from information repositories. This flaw demonstrates how filesystem characteristics can influence application security when proper case sensitivity handling is not implemented. Organizations running affected versions of Ruby on Rails should immediately apply the patch released in version 3.0.4, which properly implements template filtering regardless of filesystem case sensitivity. Additional mitigations include implementing proper input validation, using case-sensitive filesystems where possible, and conducting thorough security reviews of template resolution logic. The vulnerability serves as a reminder of the importance of considering all environmental factors, including filesystem characteristics, when implementing security controls in web applications.