CVE-2012-2877 in Chrome
Summary
by MITRE
The extension system in Google Chrome before 22.0.1229.79 does not properly handle modal dialogs, which allows remote attackers to cause a denial of service (application crash) via unspecified vectors.
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Analysis
by VulDB Data Team • 12/14/2021
The vulnerability identified as CVE-2012-2877 resides within Google Chrome's extension system and represents a significant security flaw that existed prior to version 22.0.1229.79. This issue specifically targets the browser's handling of modal dialogs within its extension architecture, creating a potential avenue for remote attackers to disrupt normal browser operations. The flaw demonstrates a critical oversight in Chrome's security model where the extension system fails to properly validate or manage modal dialog interactions, leading to unpredictable behavior that can be exploited by malicious actors. The vulnerability operates at a fundamental level within Chrome's user interface handling mechanisms, particularly affecting how the browser processes dialog boxes that are designed to block user interaction until resolved. This weakness in the extension framework creates a scenario where unauthorized code execution can occur through carefully crafted malicious extensions or web content that triggers the problematic dialog handling code path.
The technical implementation of this vulnerability stems from improper validation of modal dialog states within Chrome's extension API. When extensions attempt to display modal dialogs or interact with dialog elements, the browser's extension system fails to properly sanitize or validate these operations, allowing malicious code to manipulate dialog states in ways that were not anticipated by the original design. This flaw falls under the category of improper input validation and can be categorized as a CWE-20 vulnerability, representing weakness in input sanitization and validation. The operational impact occurs when an attacker crafts a malicious extension or web page that triggers the modal dialog handling code path in a manner that causes the browser process to crash or become unresponsive. The vulnerability is particularly dangerous because it can be triggered through legitimate extension functionality, making it difficult to distinguish between benign and malicious use of the extension API.
The potential for denial of service exploitation through this vulnerability extends beyond simple browser crashes to include more sophisticated attack vectors that can be used in conjunction with other security flaws. Attackers can leverage this weakness to create persistent disruptions in browser functionality, potentially leading to complete browser instability and requiring manual restarts to restore normal operations. The impact is particularly concerning in environments where Chrome is used extensively for business or sensitive operations, as the denial of service can effectively render the browser unusable for extended periods. This vulnerability also represents a potential stepping stone for more advanced attacks, as the instability it creates can be used to mask other malicious activities or create conditions favorable to further exploitation attempts. The attack surface is broadened by the fact that this vulnerability affects the core extension system, which is integral to Chrome's functionality and widely used by both legitimate and malicious extensions.
Mitigation strategies for CVE-2012-2877 focus primarily on immediate browser updates to version 22.0.1229.79 or later, which contains the necessary patches to address the modal dialog handling flaw. Users should also implement strict extension management policies, limiting the installation and execution of third-party extensions to only those from verified sources. Network administrators should consider implementing browser hardening measures and monitoring for unusual extension behavior patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and state management in browser extension systems, aligning with ATT&CK technique T1106 for execution through legitimate user processes. Security teams should also implement regular vulnerability assessments and penetration testing focused on browser extension security to identify similar weaknesses in other browser components or third-party applications that might present analogous risks. Organizations should maintain up-to-date threat intelligence feeds to monitor for any reported exploitation attempts targeting this specific vulnerability or similar modal dialog handling flaws in browser environments.