CVE-2006-1016 in Internet Explorer
Summary
by MITRE
Buffer overflow in the IsComponentInstalled method in Internet Explorer 6.0, when used on Windows 2000 before SP4 or Windows XP before SP1, allows remote attackers to execute arbitrary code via JavaScript that calls IsComponentInstalled with a long first argument.
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Analysis
by VulDB Data Team • 07/08/2021
The vulnerability described in CVE-2006-1016 represents a critical buffer overflow flaw in Microsoft Internet Explorer 6.0 that specifically affects Windows 2000 systems prior to Service Pack 4 and Windows XP systems prior to Service Pack 1. This security weakness resides within the IsComponentInstalled method, which is part of Internet Explorer's ActiveX component handling mechanism. The vulnerability operates by exploiting improper input validation when processing JavaScript code that invokes the IsComponentInstalled method with an excessively long first argument, creating a condition where memory boundaries are exceeded and potentially allowing malicious code execution.
The technical exploitation of this vulnerability follows a classic buffer overflow pattern where the IsComponentInstalled method fails to properly validate the length of its input parameter before processing it. When JavaScript code passes an argument that exceeds the allocated buffer space, the excess data overflows into adjacent memory locations, potentially corrupting the program's execution flow. This flaw falls under CWE-121, which categorizes buffer overflow conditions where insufficient boundary checking allows attackers to write past the end of allocated buffers. The vulnerability is particularly dangerous because it leverages the browser's JavaScript engine to trigger the overflow, making it accessible through web-based attacks without requiring any local privileges.
The operational impact of this vulnerability is severe and multifaceted, as it provides remote attackers with the capability to execute arbitrary code on vulnerable systems with the privileges of the user running Internet Explorer. This means that successful exploitation could lead to complete system compromise, allowing attackers to install malware, steal sensitive data, modify system files, or establish persistent backdoors. The vulnerability affects a significant portion of the user base at the time of discovery, as Internet Explorer 6.0 was widely deployed across Windows 2000 and XP systems, making it an attractive target for cybercriminals. The attack vector through JavaScript execution means that users could be compromised simply by visiting a malicious website or viewing a specially crafted email message containing embedded malicious code.
Mitigation strategies for this vulnerability require immediate implementation of security patches and updates from Microsoft, specifically the service packs that address the underlying buffer overflow condition. System administrators should ensure that all Windows 2000 and XP systems are updated to at least Service Pack 4 and Service Pack 1 respectively, as these updates contain the necessary code modifications to prevent the buffer overflow from occurring. Additional protective measures include implementing browser security configurations that restrict ActiveX controls, enabling zone-based security settings, and deploying intrusion detection systems that can identify suspicious JavaScript patterns. From an ATT&CK framework perspective, this vulnerability maps to techniques involving exploitation of known vulnerabilities and privilege escalation, with the attack chain typically following T1190 for exploitation of remote services and T1068 for bypassing system protections. Organizations should also consider implementing network segmentation and web application firewalls to prevent unauthorized access to vulnerable systems, while maintaining regular vulnerability assessments to identify and remediate similar issues before they can be exploited by attackers.