CVE-2004-1325 in Windows Media Player
Summary
by MITRE
The getItemInfoByAtom function in the ActiveX control for Microsoft Windows Media Player 9.0 returns a 0 if the file does not exist and the size of the file if the file exists, which allows remote attackers to determine the existence of files on the local system.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 09/25/2025
The vulnerability described in CVE-2004-1325 resides within the ActiveX control implementation of Microsoft Windows Media Player 9.0, specifically within the getItemInfoByAtom function. This flaw represents a classic information disclosure vulnerability that arises from improper handling of file existence checks within a media player component designed for rich internet applications. The vulnerability manifests when the ActiveX control processes requests for media file information, creating a scenario where attackers can infer whether specific files exist on the local system through carefully crafted remote requests. This particular implementation flaw demonstrates a fundamental security oversight in how the control manages file system interactions, creating a direct pathway for reconnaissance activities that could lead to more sophisticated attacks.
The technical mechanism behind this vulnerability operates through the inconsistent return values of the getItemInfoByAtom function. When a file does not exist, the function returns a value of zero, while for existing files it returns the file size in bytes. This design creates a deterministic response pattern that attackers can exploit to perform file enumeration attacks against systems running the vulnerable ActiveX control. The vulnerability specifically affects Windows Media Player 9.0 installations where the ActiveX control is enabled and accessible through web browsers, making it particularly dangerous in environments where users browse untrusted websites or encounter malicious web content. The flaw exists at the application layer and leverages the control's interaction with the local file system, representing a type of information disclosure vulnerability that falls under CWE-200, which describes "Information Exposure" where system information is exposed to unauthorized users.
The operational impact of this vulnerability extends beyond simple file enumeration, as it provides attackers with critical reconnaissance data that can inform subsequent attack vectors. An attacker who successfully exploits this vulnerability gains the ability to map the local file system structure, potentially identifying sensitive files, system binaries, or user data that could be targeted in further attacks. This reconnaissance capability aligns with techniques described in the MITRE ATT&CK framework under the Information Gathering tactic, specifically targeting the enumeration of system resources and file systems. The vulnerability particularly impacts organizations where Windows Media Player 9.0 is installed and enabled in browser environments, creating a persistent threat vector that can be exploited without requiring local system access or elevated privileges. The impact is significant because it allows attackers to perform systematic file existence checks across potentially thousands of files, enabling them to build detailed profiles of target systems.
Mitigation strategies for this vulnerability must address both the immediate exposure and the underlying architectural issues that enabled the flaw. Microsoft addressed this vulnerability through security updates that modified the ActiveX control's behavior to eliminate the information disclosure characteristics. Organizations should ensure that Windows Media Player 9.0 installations are either patched with the appropriate security updates or completely removed from systems where it poses an unnecessary risk. The vulnerability highlights the importance of proper input validation and output handling in ActiveX controls, as well as the need for careful security review of components that interface with local system resources. Additionally, implementing browser security policies that restrict ActiveX control usage, particularly in enterprise environments, can significantly reduce the attack surface. Network segmentation and monitoring for suspicious ActiveX control behavior can also provide early detection of exploitation attempts, while regular security assessments should include evaluation of legacy ActiveX components that may contain similar information disclosure vulnerabilities.