CVE-2016-1676 in Chrome
Summary
by MITRE
extensions/renderer/resources/binding.js in the extension bindings in Google Chrome before 51.0.2704.63 does not properly use prototypes, which allows remote attackers to bypass the Same Origin Policy via unspecified vectors.
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Analysis
by VulDB Data Team • 08/22/2022
The vulnerability identified as CVE-2016-1676 resides within the extension binding mechanism of Google Chrome, specifically in the binding.js file located in the extensions/renderer/resources directory. This flaw represents a critical security weakness that undermines the fundamental web security model by enabling malicious actors to circumvent the Same Origin Policy (SOP) which is a cornerstone of web browser security architecture. The issue manifests in how Chrome's extension system handles prototype inheritance and object property access, creating a pathway for unauthorized code execution and data access across different origins.
The technical root cause of this vulnerability stems from improper prototype usage within the extension binding framework. When Chrome processes extension API calls, it relies on prototype-based object relationships to manage access to privileged resources and maintain security boundaries between extensions and the underlying web pages. The flaw occurs when the system fails to properly validate or enforce prototype chain integrity, allowing attackers to manipulate object properties and access restricted resources through indirect means. This prototype manipulation enables attackers to construct malicious extension code that can bypass normal security restrictions and gain unauthorized access to sensitive data or functionality.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it allows remote attackers to execute arbitrary code within the context of the Chrome browser and potentially access user data across different domains. Attackers can leverage this weakness to create malicious browser extensions or exploit existing extensions to gain unauthorized access to user information, cookies, local storage, and other sensitive data stored within the browser environment. The vulnerability is particularly dangerous because it operates at the core of Chrome's extension system, where extensions have elevated privileges and can interact with web pages, making it possible for attackers to harvest sensitive information from multiple websites simultaneously.
This vulnerability aligns with CWE-284, which addresses improper access control mechanisms, and represents a specific implementation flaw in how Chrome handles prototype-based access control for extension APIs. The attack vector typically involves crafting malicious extensions or exploiting existing extensions to manipulate prototype chains and gain unauthorized access to cross-origin resources. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, as attackers can leverage the compromised extension system to access sensitive browser data and potentially escalate their access to system-level resources.
Mitigation strategies for this vulnerability require immediate patching of Chrome to version 51.0.2704.63 or later, where Google implemented proper prototype validation and access control mechanisms. Organizations should also enforce strict extension review processes, particularly for extensions that require elevated privileges, and implement monitoring systems to detect anomalous extension behavior. Browser administrators should consider disabling unnecessary extensions and regularly audit installed extensions to minimize the attack surface. Additionally, users should be educated about the risks of installing third-party extensions and the importance of only installing extensions from trusted sources, as this vulnerability can be exploited through malicious extensions that appear legitimate but contain hidden malicious code designed to exploit the prototype handling flaw.