CVE-2012-1959 in Firefox
Summary
by MITRE
Mozilla Firefox 4.x through 13.0, Firefox ESR 10.x before 10.0.6, Thunderbird 5.0 through 13.0, Thunderbird ESR 10.x before 10.0.6, and SeaMonkey before 2.11 do not consider the presence of same-compartment security wrappers (SCSW) during the cross-compartment wrapping of objects, which allows remote attackers to bypass intended XBL access restrictions via crafted content.
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Analysis
by VulDB Data Team • 10/21/2024
The vulnerability described in CVE-2012-1959 represents a critical security flaw in Mozilla Firefox and related applications that affects versions ranging from Firefox 4.x through 13.0, Firefox ESR 10.x before 10.0.6, Thunderbird 5.0 through 13.0, Thunderbird ESR 10.x before 10.0.6, and SeaMonkey before 2.11. This issue stems from the improper handling of same-compartment security wrappers during cross-compartment object wrapping operations, creating a significant bypass mechanism for XBL access restrictions that should normally protect against malicious content execution.
The technical root cause of this vulnerability lies in the browser's security architecture where same-compartment security wrappers are designed to prevent unauthorized access between different security contexts. However, the implementation fails to properly account for these SCSW mechanisms when performing cross-compartment wrapping operations, allowing malicious actors to craft content that can bypass the intended security boundaries. This flaw specifically affects the XBL (XML Binding Language) access controls that are crucial for maintaining separation between privileged and unprivileged code execution contexts within the browser's rendering engine.
The operational impact of this vulnerability is severe as it enables remote attackers to execute arbitrary code with elevated privileges by exploiting the bypass mechanism. Attackers can craft malicious web content that appears to be legitimate but can access restricted XBL functionality through the compromised cross-compartment wrapping process. This creates a pathway for privilege escalation attacks where untrusted content can gain access to privileged browser APIs and potentially compromise the entire user session or system. The vulnerability affects not just web browsing but also email client functionality through Thunderbird and the SeaMonkey suite, expanding the potential attack surface significantly.
From a cybersecurity perspective, this vulnerability aligns with CWE-284 (Improper Access Control) and represents a classic example of insufficient privilege checking in security-critical code paths. The ATT&CK framework categorizes this as a privilege escalation technique through browser exploitation, specifically targeting the browser's security model and object access controls. The flaw demonstrates the complexity of modern browser security architectures where multiple compartments must maintain strict isolation while still allowing legitimate cross-domain communication. Organizations affected by this vulnerability should immediately implement patches and updates to their browser installations, while security teams should monitor for potential exploitation attempts in their network traffic. The vulnerability also underscores the importance of proper security wrapper implementation and the necessity of thorough testing of cross-compartment security mechanisms in complex software environments.
Mitigation strategies should include immediate deployment of vendor security patches, implementation of network-based protections such as web application firewalls, and enhanced monitoring for suspicious cross-compartment access patterns. Security administrators should also consider implementing browser hardening measures and restricting access to potentially vulnerable browser features until comprehensive updates are deployed. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches and the inherent risks present in complex browser security models that must balance functionality with protection against sophisticated attack vectors.