CVE-2004-0727 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 6.0.2800.1106 on Microsoft Windows XP SP2, and other versions including 5.01 and 5.5, allows remote web servers to bypass zone restrictions and execute arbitrary code in the local computer zone by redirecting a function to another function with the same name, as demonstrated by SimilarMethodNameRedir, aka the "Similar Method Name Redirection Cross Domain Vulnerability."
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Analysis
by VulDB Data Team • 09/15/2025
The vulnerability identified as CVE-2004-0727 represents a critical cross-domain security flaw in Microsoft Internet Explorer versions 5.01, 5.5, and 6.0.2800.1106 running on Windows XP SP2 and related systems. This vulnerability specifically targets the browser's security model that enforces zone restrictions to prevent malicious code execution across different security domains. The flaw exploits the browser's handling of method name redirection between different domains, allowing attackers to bypass the security boundaries that normally protect users from potentially harmful content. The vulnerability operates through a sophisticated technique where malicious web servers can manipulate the browser's object model to redirect function calls from one domain to another, effectively circumventing the security restrictions that should prevent cross-domain code execution.
The technical implementation of this vulnerability leverages the browser's JavaScript engine's method resolution mechanism, where functions with similar names can be confused or incorrectly resolved across domain boundaries. When Internet Explorer encounters a method call that should be restricted due to cross-domain access, an attacker can craft malicious content that causes the browser to redirect execution to a function with the same name but located in a different security zone. This redirection technique, demonstrated through the SimilarMethodNameRedir exploit, allows attackers to execute arbitrary code within the local computer zone, which typically has higher privileges than remote content. The vulnerability specifically affects how the browser handles method resolution and object model access, creating a pathway for privilege escalation that bypasses the standard security mechanisms designed to protect users from malicious web content.
The operational impact of this vulnerability is severe and far-reaching, as it enables attackers to execute arbitrary code on vulnerable systems with the privileges of the local user account. This represents a critical compromise of the browser's security architecture, allowing remote attackers to perform actions such as installing malicious software, modifying system files, accessing sensitive data, or establishing persistent backdoors. The vulnerability affects not only individual users but also enterprise environments where multiple users may be running vulnerable versions of Internet Explorer. Attackers can leverage this vulnerability through various attack vectors including malicious websites, phishing emails with embedded web content, or compromised legitimate websites that have been exploited to deliver malicious payloads. The attack requires minimal user interaction beyond visiting a malicious website, making it particularly dangerous in real-world scenarios.
Organizations and security professionals should prioritize immediate mitigation of this vulnerability through several approaches. The most effective solution involves updating to patched versions of Internet Explorer, specifically Microsoft Internet Explorer 6.0 Service Pack 1 or later, which addressed the method name redirection issue through enhanced security model implementations. Additionally, implementing browser security configurations such as disabling active scripting for untrusted sites, configuring security zones appropriately, and deploying application whitelisting solutions can provide additional defense layers. Network-level protections including web application firewalls and content filtering solutions can help detect and block malicious redirection attempts. The vulnerability aligns with CWE-284 (Improper Access Control) and represents a classic example of privilege escalation through cross-domain scripting attacks that would be categorized under ATT&CK technique T1059.007 (Command and Scripting Interpreter: JavaScript) and T1566 (Phishing) in threat modeling frameworks. Organizations should also consider implementing security awareness training to help users recognize potentially malicious web content and avoid visiting compromised websites that may exploit this vulnerability.