CVE-2012-4193 in Firefox
Summary
by MITRE
Mozilla Firefox before 16.0.1, Firefox ESR 10.x before 10.0.9, Thunderbird before 16.0.1, Thunderbird ESR 10.x before 10.0.9, and SeaMonkey before 2.13.1 omit a security check in the defaultValue function during the unwrapping of security wrappers, which allows remote attackers to bypass the Same Origin Policy and read the properties of a Location object, or execute arbitrary JavaScript code, via a crafted web site.
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Analysis
by VulDB Data Team • 10/22/2024
The vulnerability identified as CVE-2012-4193 represents a critical security flaw in Mozilla Firefox and related applications that persisted across multiple versions including Firefox 16.0.1, Thunderbird 16.0.1, and SeaMonkey 2.13.1. This issue stems from an insufficient security check within the defaultValue function during the unwrapping process of security wrappers, creating a significant bypass opportunity for malicious actors. The vulnerability specifically targets the Same Origin Policy implementation which serves as a fundamental security mechanism in web browsers to prevent unauthorized access between different origins. The flaw allows attackers to circumvent these protective measures and gain unauthorized access to Location object properties that should normally be restricted.
The technical implementation of this vulnerability occurs during the JavaScript security wrapper unwrapping process where Firefox fails to properly validate the security context before allowing access to sensitive object properties. When a web page attempts to access the defaultValue function of a security wrapper, the application does not adequately verify whether the requesting context has proper authorization to access the underlying Location object properties. This oversight creates a path for remote code execution through crafted web content that can manipulate the unwrapping process to access restricted data and potentially execute arbitrary JavaScript code within the browser environment. The vulnerability essentially allows attackers to escalate privileges by bypassing the normal security boundaries that should prevent cross-origin data access.
The operational impact of this vulnerability extends beyond simple data theft, as it provides attackers with the capability to perform full browser exploitation and potentially gain control over user sessions. Security researchers have classified this as a serious issue that can be exploited through malicious websites to harvest sensitive information from user browsers, including location data and other properties of the Location object that might contain session identifiers or other confidential information. The vulnerability is particularly dangerous because it operates at the core security layer of the browser, making it difficult to detect and prevent through conventional security measures. This flaw affects not just Firefox but also Thunderbird and SeaMonkey applications, indicating a widespread impact across Mozilla's ecosystem of products.
Organizations and users should immediately update to patched versions of affected software to mitigate this vulnerability, as the security implications extend to user privacy and session security. The vulnerability aligns with CWE-284 Access Control Issues, specifically related to insufficient access control mechanisms in security wrapper implementations. From an ATT&CK framework perspective, this vulnerability maps to T1059 Command and Scripting Interpreter and T1071.1 Application Layer Protocol Web Protocols, as it enables attackers to execute malicious JavaScript code through web-based attacks. Additionally, it represents a privilege escalation vector that could lead to more severe consequences including persistent access to user systems. System administrators should implement immediate patch management procedures and consider network monitoring for suspicious web traffic patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and the potential consequences of failing to address security flaws in core browser functionality.