CVE-2012-3993 in Firefox
Summary
by MITRE
The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbird before 16.0, Thunderbird ESR 10.x before 10.0.8, and SeaMonkey before 2.13 does not properly interact with failures of InstallTrigger methods, which allows remote attackers to execute arbitrary JavaScript code with chrome privileges via a crafted web site, related to an "XrayWrapper pollution" issue.
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Analysis
by VulDB Data Team • 10/22/2024
The vulnerability described in CVE-2012-3993 represents a critical security flaw in Mozilla Firefox and related browser applications that stems from improper handling of Chrome Object Wrapper interactions within the browser's security architecture. This issue affects multiple Mozilla products including Firefox versions prior to 16.0, Firefox ESR 10.x versions prior to 10.0.8, Thunderbird versions prior to 16.0, Thunderbird ESR 10.x versions prior to 10.0.8, and SeaMonkey versions prior to 2.13. The vulnerability specifically relates to how the browser handles failures in InstallTrigger methods, creating a pathway for remote code execution with elevated chrome privileges.
The technical root cause of this vulnerability lies in the Chrome Object Wrapper implementation, which serves as a security mechanism designed to isolate privileged chrome code from untrusted web content. When InstallTrigger methods fail during the execution process, the COW implementation does not properly handle these failure conditions, leading to what security researchers term "XrayWrapper pollution." This pollution allows malicious web content to manipulate the security boundaries that should protect chrome-level code from being directly accessible to web pages. The flaw essentially creates a scenario where attacker-controlled JavaScript can bypass security restrictions and gain access to privileged chrome APIs that should remain protected from web-based exploitation.
The operational impact of this vulnerability is severe as it enables remote attackers to execute arbitrary JavaScript code with chrome privileges, which represents a significant escalation from typical web-based attacks. Chrome privileges provide access to powerful browser functionalities including direct access to the file system, network operations, and other system-level capabilities that are normally restricted from web content. This vulnerability allows attackers to craft malicious websites that can exploit the COW implementation failure to gain unauthorized access to privileged browser functions, potentially leading to complete browser compromise, data theft, or further system exploitation. The attack vector requires only a user to visit a malicious website, making it particularly dangerous in phishing campaigns or drive-by download scenarios.
This vulnerability maps to CWE-264 in the Common Weakness Enumeration catalog, which specifically addresses "Permissions, Privileges, and Access Controls" and more specifically relates to improper handling of privilege escalation scenarios. From the MITRE ATT&CK framework perspective, this vulnerability corresponds to techniques involving privilege escalation and code execution in the browser context, potentially enabling later stages of attack such as credential theft, system reconnaissance, or persistence mechanisms. The exploitation of this vulnerability demonstrates the importance of proper error handling in security-critical components, as failure to properly manage exceptional conditions in privileged code can create dangerous attack surfaces. Organizations should implement immediate mitigations including updating to patched versions of affected software, as well as monitoring for suspicious browser behavior or attempts to access privileged APIs that might indicate exploitation attempts. The vulnerability underscores the critical need for robust security boundaries in modern web browsers and highlights how seemingly minor implementation flaws in security mechanisms can result in significant privilege escalation capabilities for attackers.