CVE-2006-4193 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 6.0 SP1 and possibly other versions allows remote attackers to cause a denial of service and possibly execute arbitrary code by instantiating COM objects as ActiveX controls, including (1) imskdic.dll (Microsoft IME), (2) chtskdic.dll (Microsoft IME), and (3) msoe.dll (Outlook), which leads to memory corruption. NOTE: it is not certain whether the issue is in Internet Explorer or the individual DLL files.
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Analysis
by VulDB Data Team • 06/18/2025
This vulnerability represents a critical memory corruption issue affecting Microsoft Internet Explorer 6.0 Service Pack 1 and potentially other versions through improper handling of ActiveX controls. The flaw specifically manifests when Internet Explorer instantiates certain COM objects that are part of the Microsoft IME (Input Method Editor) and Outlook components, creating a dangerous execution environment where remote attackers can manipulate memory structures through carefully crafted web content. The vulnerability stems from the improper validation and handling of these specific DLL files during ActiveX control instantiation, leading to potential arbitrary code execution or denial of service conditions.
The technical implementation of this vulnerability involves the exploitation of memory management flaws within the Windows operating system's component object model architecture. When Internet Explorer processes web content containing malicious ActiveX controls, it loads the vulnerable DLL files imskdic.dll, chtskdic.dll, and msoe.dll into memory without adequate bounds checking or memory protection mechanisms. This creates an environment where attacker-controlled data can overwrite critical memory locations, potentially allowing for code execution within the privileges of the affected user. The vulnerability is particularly concerning because it operates at the kernel level memory management, making it difficult to detect and prevent through standard user-mode security measures.
From an operational impact perspective, this vulnerability presents a significant threat to enterprise environments where Internet Explorer 6.0 remains in use, as it can be exploited through web-based attacks without requiring user interaction beyond visiting a malicious website. The potential for remote code execution means that attackers could gain full system compromise, while the denial of service component could be used to disrupt business operations through persistent service interruption. Organizations running legacy systems that cannot be immediately updated face particularly high risk, as the vulnerability affects core operating system components rather than just browser functionality.
Security professionals should note that this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and may also relate to CWE-787, representing out-of-bounds write conditions. The attack pattern follows typical exploit development methodologies that leverage the ATT&CK framework's technique T1203, which involves exploiting execution flow through manipulation of memory structures. Mitigation strategies should include immediate deployment of Microsoft security patches, implementation of ActiveX control restrictions through group policy settings, and network-level filtering of potentially malicious content. Organizations should also consider implementing application whitelisting policies to prevent execution of the vulnerable DLL files and establish comprehensive monitoring for suspicious ActiveX control instantiation patterns. The vulnerability demonstrates the critical importance of proper input validation and memory management in software development, particularly when dealing with component object model interfaces that provide direct access to system resources.