CVE-2006-1733 in Firefox
Summary
by MITRE
Mozilla Firefox and Thunderbird 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 does not properly protect the compilation scope of privileged built-in XBL bindings, which allows remote attackers to execute arbitrary code via the (1) valueOf.call or (2) valueOf.apply methods of an XBL binding, or (3) "by inserting an XBL method into the DOM s document.body prototype chain."
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Analysis
by VulDB Data Team • 01/20/2025
This vulnerability resides in the cross-boundary security mechanisms of Mozilla's browser and email applications, specifically targeting the privileged XBL binding compilation scope protection. The flaw affects versions of Firefox, Thunderbird, Mozilla Suite, and SeaMonkey prior to their respective security patches, creating a critical exploitation vector that allows remote code execution through improper handling of privileged built-in XBL bindings. The vulnerability stems from insufficient protection of the compilation scope within XBL (XML Binding Language) bindings that are designed to operate with elevated privileges in the browser's security context.
The technical exploitation occurs through three distinct methods that leverage the weaknesses in how the browser handles privileged XBL bindings. Attackers can utilize the valueOf.call or valueOf.apply methods of an XBL binding to manipulate the execution flow, or alternatively insert an XBL method directly into the DOM document.body prototype chain. These approaches exploit the fundamental flaw in the privilege separation mechanism that should prevent untrusted code from accessing or manipulating privileged binding contexts. The vulnerability represents a classic case of privilege escalation through improper access control in the browser's security model.
The operational impact of this vulnerability is severe, as it enables remote attackers to execute arbitrary code with the privileges of the browser process itself. This means that successful exploitation could lead to complete system compromise without requiring local user interaction beyond visiting a malicious webpage. The vulnerability affects not just the browser's rendering engine but also its underlying security architecture, potentially allowing attackers to bypass other security measures such as sandboxing and privilege separation mechanisms. The attack surface is particularly broad given that the affected software versions were widely distributed and used across different platforms and operating systems.
Mitigation strategies for this vulnerability require immediate patching of all affected software versions, as the flaw represents a critical security risk that cannot be effectively mitigated through configuration changes or workarounds. Organizations should prioritize updating to the patched versions of Firefox 1.5, Thunderbird 1.0.8, Mozilla Suite 1.7.13, and SeaMonkey 1.0, which contain the necessary fixes for the XBL binding scope protection. The vulnerability aligns with CWE-284, which addresses improper access control, and maps to ATT&CK technique T1059.007 for execution through JavaScript, specifically targeting the browser's scripting engine. Security teams should also implement network-based protections such as web application firewalls and content filtering to prevent access to known malicious domains until full patching is achieved.