CVE-2014-8636 in Firefox
Summary
by MITRE
The XrayWrapper implementation in Mozilla Firefox before 35.0 and SeaMonkey before 2.32 does not properly interact with a DOM object that has a named getter, which might allow remote attackers to execute arbitrary JavaScript code with chrome privileges via unspecified vectors.
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Analysis
by VulDB Data Team • 12/23/2024
The vulnerability described in CVE-2014-8636 represents a critical security flaw within the XrayWrapper implementation of Mozilla Firefox and SeaMonkey browsers. This issue affects versions prior to Firefox 35.0 and SeaMonkey 2.32, where the browser's security model fails to properly handle DOM objects that contain named getters. The flaw exists in the way these browsers process cross-origin object access, specifically when dealing with objects that implement named getters in their prototype chains. This misconfiguration creates a privilege escalation vector that allows remote attackers to execute malicious JavaScript code with chrome privileges, which are the highest level of privileges available within the browser environment.
The technical root cause of this vulnerability lies in the improper interaction between the XrayWrapper mechanism and DOM objects possessing named getters. XrayWrapper is designed to provide a secure bridge between different security contexts in web applications, but when a DOM object contains a named getter, the wrapper implementation fails to properly sanitize or validate the access patterns. This allows attackers to craft malicious web pages that can bypass security restrictions and gain access to privileged chrome-level JavaScript execution capabilities. The vulnerability is particularly dangerous because it operates at the core of Firefox's security architecture, specifically affecting how the browser handles cross-origin resource access and object property resolution. According to CWE-284, this represents an improper access control vulnerability where the system fails to properly restrict access to privileged resources.
The operational impact of this vulnerability is severe and far-reaching for users of affected browser versions. Attackers can exploit this flaw to execute arbitrary JavaScript code with chrome privileges, which grants them access to the full browser chrome context and potentially sensitive user data. This includes the ability to access other domains' resources, manipulate browser internals, and potentially exfiltrate user information. The attack surface is broad since the vulnerability can be triggered through various web page vectors, including malicious websites, phishing attacks, or compromised legitimate sites. The exploitability factor is high because the vulnerability allows for remote code execution without requiring user interaction beyond visiting a malicious page, making it particularly dangerous in real-world scenarios. This aligns with ATT&CK technique T1059.007 for JavaScript execution and T1068 for privilege escalation.
The recommended mitigation strategy involves immediate upgrade to Firefox version 35.0 or later and SeaMonkey version 2.32 or later, where the vulnerability has been patched. Organizations should implement comprehensive browser update policies to ensure all users are running patched versions. Additionally, administrators should consider implementing content security policies and monitoring for suspicious JavaScript execution patterns. The patch addresses the core issue by properly handling the interaction between XrayWrapper and named getter objects, ensuring that privilege boundaries are maintained even when complex DOM object structures are involved. Security teams should also monitor for any attempts to exploit this vulnerability in the wild and maintain updated threat intelligence feeds to detect related attack patterns.