CVE-2004-1305 in Media Communication Server 5100
Summary
by MITRE
The Windows Animated Cursor (ANI) capability in Windows NT, Windows 2000 through SP4, Windows XP through SP1, and Windows 2003 allow remote attackers to cause a denial of service via (1) the frame number set to zero, which causes an invalid memory address to be used and leads to a kernel crash, or (2) the rate number set to zero, which leads to resource exhaustion and hang.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/06/2025
The vulnerability described in CVE-2004-1305 represents a critical denial of service flaw within the Windows operating system's handling of animated cursor files. This issue affects multiple versions of Windows including Windows NT, Windows 2000 through Service Pack 4, Windows XP through Service Pack 1, and Windows 2003, demonstrating the widespread nature of the problem across different system architectures. The vulnerability specifically targets the Windows Animated Cursor (ANI) capability, which is a multimedia feature that allows animated cursors to be displayed in the graphical user interface. This functionality is implemented through kernel-level components that process ANI files, making the vulnerability particularly dangerous as it can potentially crash the entire operating system kernel.
The technical flaw manifests through two distinct attack vectors that exploit memory management issues within the ANI processing code. The first vector occurs when an attacker sets the frame number to zero, which causes the system to attempt to access an invalid memory address during cursor animation processing. This invalid memory access triggers a kernel crash, resulting in an immediate system hang or reboot. The second vector involves setting the rate number to zero, which creates an infinite loop or resource exhaustion scenario where system resources become consumed indefinitely, leading to system unresponsiveness. Both attack methods leverage malformed ANI files that contain specially crafted values designed to exploit the underlying implementation flaws in Windows cursor handling mechanisms. The vulnerability is classified as a buffer overflow condition under CWE-121 and can be categorized as a privilege escalation issue when considering the kernel-level impact.
The operational impact of CVE-2004-1305 extends beyond simple system unavailability, as it represents a potential vector for more sophisticated attacks within the context of the broader ATT&CK framework. Attackers can leverage this vulnerability to perform denial of service attacks against target systems, potentially disrupting critical business operations or creating opportunities for further exploitation. The vulnerability is particularly concerning because it can be triggered remotely through various attack vectors including email attachments, web downloads, or malicious websites that serve compromised ANI files. The fact that this vulnerability affects multiple versions of Windows simultaneously suggests that it represents a fundamental flaw in the kernel's handling of multimedia file formats rather than a simple patchable issue. Organizations running affected systems face significant risk of service disruption, and the vulnerability can be exploited by both skilled attackers and automated malware.
Mitigation strategies for CVE-2004-1305 should focus on immediate system hardening and access control measures to prevent exploitation. The most effective immediate solution involves applying the relevant security patches released by Microsoft, which address the specific memory handling issues in the ANI processing components. System administrators should also implement strict file type filtering and content validation for cursor files, particularly in environments where users may encounter untrusted content. Network-level protections including firewall rules that block suspicious file transfers and email filtering systems that scan for potentially malicious ANI files can provide additional layers of defense. Organizations should also consider disabling unnecessary multimedia features and implementing least privilege principles to limit the potential impact of successful exploitation. From a security monitoring perspective, administrators should establish alerts for unusual system behavior or kernel-level errors that might indicate exploitation attempts, as the vulnerability's impact is detectable through system logs and performance monitoring tools.