CVE-2016-2336 in Ruby
Summary
by MITRE
Type confusion exists in two methods of Ruby's WIN32OLE class, ole_invoke and ole_query_interface. Attacker passing different type of object than this assumed by developers can cause arbitrary code execution.
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Analysis
by VulDB Data Team • 04/20/2025
The vulnerability identified as CVE-2016-2336 represents a critical type confusion flaw within Ruby's WIN32OLE class, specifically affecting the ole_invoke and ole_query_interface methods. This vulnerability stems from improper type validation and handling within the object-oriented programming interface that Ruby provides for Windows COM automation. The flaw allows attackers to manipulate object types during method invocation, creating a scenario where the runtime environment executes code based on incorrect type assumptions. Such type confusion vulnerabilities are particularly dangerous because they can lead to memory corruption and arbitrary code execution, making them a prime target for exploitation in various attack scenarios.
The technical implementation of this vulnerability involves the WIN32OLE class's interaction with Windows COM objects through the ole_invoke and ole_query_interface methods. When these methods process incoming parameters, they assume specific object types based on developer expectations. However, an attacker can supply objects of different types than anticipated, causing the runtime to misinterpret memory layout and execute unintended code paths. This type confusion occurs at the binary level where the interpreter expects certain memory structures but receives different ones, leading to potential buffer overflows or instruction pointer corruption. The vulnerability manifests when Ruby's object model fails to properly validate type information before executing method calls, creating an opportunity for attackers to manipulate the execution flow through carefully crafted object parameters.
The operational impact of CVE-2016-2336 extends beyond simple code execution to encompass potential system compromise and privilege escalation scenarios. Attackers can leverage this vulnerability to execute malicious code with the privileges of the affected Ruby process, which typically runs with the permissions of the user account that initiated the Ruby interpreter. In environments where Ruby applications interact with Windows COM objects, such as in enterprise automation scripts or web applications using Ruby on Rails, this vulnerability presents a significant threat vector. The attack surface is particularly wide in Windows environments where COM automation is prevalent, making systems running vulnerable Ruby versions susceptible to remote code execution attacks. This vulnerability aligns with CWE-471, which specifically addresses the issue of type confusion in programming languages where the system fails to properly validate object types during runtime operations.
Mitigation strategies for CVE-2016-2336 require immediate patching of affected Ruby installations to versions that address the type validation issues in the WIN32OLE class. System administrators should prioritize updating Ruby environments, particularly in production systems where COM automation is utilized. Additionally, implementing network segmentation and access controls can limit the attack surface by restricting which systems can interact with vulnerable Ruby applications. Input validation should be strengthened at application level to ensure that object types passed to ole_invoke and ole_query_interface methods are properly validated before processing. Organizations should also consider disabling unnecessary COM automation features in Ruby applications and implementing runtime monitoring to detect anomalous object type behaviors. The vulnerability demonstrates the importance of following secure coding practices as outlined in the ATT&CK framework's mitigation strategies for preventing type confusion attacks, emphasizing the need for proper type checking and validation in interpreted languages that interface with system-level components.