CVE-2005-1990 in Internet Explorer
Summary
by MITRE
Internet Explorer 5.0, 5.5, and 6.0 allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a web page with embedded CLSIDs that reference certain COM objects that are not ActiveX controls, including (1) devenum.dll, (2) diactfrm.dll, (3) wmm2filt.dll, (4) fsusd.dll, (5) dmdskmgr.dll, (6) browsewm.dll, (7) browseui.dll, (8) shell32.dll, (9) mshtml.dll, (10) inetcfg.dll, (11) infosoft.dll, (12) query.dll, (13) syncui.dll, (14) clbcatex.dll, (15) clbcatq.dll, (16) comsvcs.dll, and (17) msconf.dll, which causes memory corruption, aka "COM Object Instantiation Memory Corruption Vulnerability," a different vulnerability than CVE-2005-2087.
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Analysis
by VulDB Data Team • 06/30/2025
The vulnerability described in CVE-2005-1990 represents a critical memory corruption issue affecting multiple versions of Microsoft Internet Explorer including 5.0, 5.5, and 6.0. This flaw specifically targets the way Internet Explorer handles COM object instantiation through CLSIDs embedded in web pages, creating a pathway for remote attackers to exploit system stability and potentially gain unauthorized code execution privileges. The vulnerability stems from improper validation of COM objects that are not properly classified as ActiveX controls, making it distinct from other similar vulnerabilities such as CVE-2005-2087 which addresses different aspects of COM object handling. The affected components span across multiple system DLLs including devenum.dll, diactfrm.dll, wmm2filt.dll, and several others that are fundamental to Windows multimedia and system integration services.
The technical exploitation mechanism involves crafting malicious web pages that contain embedded CLSIDs referencing specific COM objects that are not properly validated by Internet Explorer's security model. When these objects are instantiated during page rendering, the browser's memory management system encounters unexpected behavior due to improper memory allocation and deallocation patterns. This leads to memory corruption that manifests as application crashes or more severe system instability. The vulnerability is particularly dangerous because it can be triggered through simple web browsing activities, making it an ideal candidate for drive-by download attacks. The attack vector operates at the application layer and leverages the trust model inherent in Windows COM architecture, where legitimate system components are treated as safe for instantiation without proper sandboxing or validation.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as the memory corruption can potentially be leveraged for arbitrary code execution. This represents a significant escalation from basic DoS conditions to full system compromise, especially when combined with other exploitation techniques or when the target system has additional vulnerabilities. The affected DLLs span critical system components including shell32.dll which handles Windows shell operations, mshtml.dll responsible for HTML rendering, and comsvcs.dll which manages COM+ services, making the attack surface particularly broad. The vulnerability affects systems running Windows 2000, Windows XP, and Windows Server 2003, which were prevalent during the time this vulnerability was discovered. This issue directly correlates with CWE-121, which describes heap-based buffer overflow conditions, and can be mapped to ATT&CK technique T1059 for execution through system components.
Mitigation strategies for this vulnerability require immediate patch deployment from Microsoft, as the primary fix involves updating Internet Explorer to versions that properly validate COM object instantiation and implement proper memory management practices. Organizations should implement browser hardening measures including disabling automatic execution of ActiveX controls, restricting access to potentially vulnerable COM objects through registry modifications, and deploying web application firewalls that can detect and block malicious CLSID references. Additionally, users should be educated about the risks of visiting untrusted websites and downloading content from unknown sources. The vulnerability highlights the importance of proper input validation and memory safety practices in application development, particularly when dealing with system-level components that interact with the operating system's core services. Security administrators should monitor for exploitation attempts through network traffic analysis and implement intrusion detection systems capable of identifying patterns associated with this specific vulnerability. Given the nature of the flaw, the recommended approach includes both immediate patch management and layered security controls to protect against potential exploitation attempts.