CVE-2004-1623 in Windows
Summary
by MITRE
The WAV file property handler in Windows XP SP1 allows remote attackers to cause a denial of service (infinite loop in Explorer) via a WAV file with an invalid file header whose fmt chunk length is set to 0xFFFFFFFF.
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Analysis
by VulDB Data Team • 07/31/2025
The vulnerability described in CVE-2004-1623 represents a critical denial of service flaw affecting Windows XP Service Pack 1 systems, specifically within the Windows Audio Waveform Audio File (WAV) property handler component. This vulnerability demonstrates how malformed multimedia file structures can be exploited to disrupt normal system operations, particularly impacting the Windows Explorer application which is central to user interaction with file systems. The issue resides in the way Windows processes WAV file metadata, specifically when encountering invalid header structures that fall outside the standard file format specifications.
The technical flaw manifests through an invalid file header construction where the fmt chunk length field is deliberately set to 0xFFFFFFFF, which represents the maximum value for a 32-bit unsigned integer. This particular value causes the property handler to enter an infinite loop during the parsing process, as the system attempts to process what appears to be an extremely large format chunk. The property handler's implementation lacks proper validation of the fmt chunk length parameter, leading to unbounded iteration or recursive processing that consumes system resources indefinitely. This behavior aligns with CWE-129, which addresses improper validation of length parameters, and demonstrates how inadequate input validation can lead to resource exhaustion vulnerabilities.
The operational impact of this vulnerability extends beyond simple system disruption, as it can effectively render the Windows Explorer interface unusable for extended periods. When a user attempts to view or interact with the malicious WAV file through Windows Explorer, the application becomes unresponsive, requiring manual intervention to terminate the process. This denial of service condition affects the user experience significantly and can potentially be exploited in larger attack scenarios where multiple system resources are consumed. The vulnerability particularly impacts desktop environments where users frequently interact with multimedia files and where the Windows Explorer interface serves as the primary file management tool.
Mitigation strategies for this vulnerability should focus on immediate system updates and enhanced file validation mechanisms. Microsoft addressed this issue through subsequent security updates, but organizations should implement additional protective measures including file type validation at network boundaries, implementation of automated file scanning systems, and user education regarding suspicious file attachments. The vulnerability highlights the importance of robust input validation in multimedia processing components and demonstrates how seemingly benign file format parsing can become a vector for system disruption. Organizations should also consider implementing application whitelisting policies to restrict execution of potentially malicious files and ensure that all system components undergo regular security assessments to identify similar validation flaws. This vulnerability serves as a reminder of the critical need for comprehensive input validation across all system components, particularly those handling user-supplied data in multimedia formats.