CVE-2014-0082 in Ruby on Rails
Summary
by MITRE
actionpack/lib/action_view/template/text.rb in Action View in Ruby on Rails 3.x before 3.2.17 converts MIME type strings to symbols during use of the :text option to the render method, which allows remote attackers to cause a denial of service (memory consumption) by including these strings in headers.
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Analysis
by VulDB Data Team • 02/01/2022
CVE-2014-0082 represents a denial of service vulnerability affecting Ruby on Rails applications running version 3.x before 3.2.17. This vulnerability resides in the actionpack/lib/action_view/template/text.rb component of the framework where MIME type strings are converted to symbols during template rendering operations. The flaw specifically manifests when the render method utilizes the :text option, creating a condition where attacker-controlled input can be processed through this symbol conversion mechanism. The vulnerability stems from the improper handling of user-supplied data within the template processing pipeline, allowing malicious actors to manipulate HTTP headers with specially crafted MIME type strings that trigger excessive memory allocation.
The technical exploitation of this vulnerability occurs through the conversion of MIME type strings to Ruby symbols, a process that lacks proper input validation and sanitization. When attackers include maliciously crafted strings in HTTP headers that are subsequently processed by the render method with the :text option, the symbol conversion process consumes disproportionate amounts of memory. This memory consumption grows exponentially with each malicious request, leading to system resource exhaustion and eventual application unresponsiveness. The vulnerability operates at the application layer and can be classified under CWE-400 as an excessive resource consumption, specifically targeting memory allocation patterns within the Ruby on Rails framework.
The operational impact of CVE-2014-0082 extends beyond simple service disruption to potentially compromise entire application availability. Attackers can systematically consume memory resources through repeated requests, causing the application server to become unresponsive or crash entirely. This type of denial of service attack can be executed remotely without requiring authentication, making it particularly dangerous in production environments. The vulnerability affects applications that process user input through HTTP headers and utilize the render method with text options, which is a common pattern in web applications. Organizations running affected Rails versions face significant risk of operational disruption and potential financial loss due to service unavailability.
Mitigation strategies for CVE-2014-0082 primarily involve upgrading to Ruby on Rails version 3.2.17 or later, which contains the necessary patches to address the symbol conversion vulnerability. Additionally, implementing input validation and sanitization measures can help prevent malicious strings from reaching the vulnerable code path. Organizations should also consider deploying web application firewalls and rate limiting mechanisms to detect and block suspicious header patterns. The vulnerability aligns with ATT&CK technique T1499.004 for resource exhaustion attacks and demonstrates the importance of proper input handling in preventing denial of service conditions. Security teams should conduct comprehensive testing to ensure that all applications using affected Rails versions are properly patched and that monitoring systems are configured to detect unusual memory consumption patterns that may indicate exploitation attempts.