CVE-2009-1546 in Windows
Summary
by MITRE
Integer overflow in Avifil32.dll in the Windows Media file handling functionality in Microsoft Windows allows remote attackers to execute arbitrary code on a Windows 2000 SP4 system via a crafted AVI file, or cause a denial of service on a Windows XP SP2 or SP3, Server 2003 SP2, Vista Gold, SP1, or SP2, or Server 2008 Gold or SP2 system via a crafted AVI file, aka "AVI Integer Overflow Vulnerability."
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Analysis
by VulDB Data Team • 04/13/2025
The CVE-2009-1546 vulnerability represents a critical integer overflow flaw within Avifil32.dll, a core component of Microsoft Windows Media file handling functionality. This vulnerability specifically targets the processing of AVI (Audio Video Interleave) files and affects multiple Windows operating systems including Windows 2000 SP4, Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista Gold and SP1/SP2, and Windows Server 2008 Gold and SP2. The flaw stems from improper input validation during the parsing of AVI file headers, where the software fails to adequately check integer values before performing arithmetic operations that could result in overflow conditions.
The technical implementation of this vulnerability occurs when the Avifil32.dll library processes malformed AVI files containing specially crafted integer values in their headers. When these values exceed the maximum representable value for the data type being used, an integer overflow occurs, leading to unpredictable behavior in memory allocation and buffer handling. This overflow condition can be exploited by attackers who craft malicious AVI files with manipulated header fields, particularly those controlling frame dimensions, sample rates, or chunk sizes. The vulnerability manifests differently across affected platforms, with Windows 2000 SP4 being susceptible to remote code execution while newer versions primarily experience denial of service conditions, though the underlying mechanism remains consistent.
The operational impact of this vulnerability extends beyond simple system instability, as it provides attackers with potential pathways for remote code execution on older systems. The integer overflow creates conditions where attacker-controlled data can overwrite adjacent memory locations, potentially allowing for stack buffer overflows or heap corruption that could be leveraged to execute arbitrary code with the privileges of the affected process. This makes the vulnerability particularly dangerous in environments where users might unknowingly open malicious media files, such as through email attachments, web downloads, or file sharing networks. The vulnerability affects both client and server systems, making it a significant concern for organizations running legacy Windows 2000 systems or those that have not properly patched their systems.
Mitigation strategies for CVE-2009-1546 require immediate patching of affected systems through Microsoft security updates, specifically addressing the integer overflow in Avifil32.dll. Organizations should implement network-based protections such as AVI file content filtering at perimeter defenses to prevent malicious files from reaching end-user systems. Additionally, user education regarding the dangers of opening untrusted media files and system hardening through disabling unnecessary media playback capabilities can reduce attack surface. The vulnerability aligns with CWE-190, Integer Overflow or Wraparound, and maps to ATT&CK technique T1203, Exploitation for Client Execution, highlighting its potential for client-side exploitation. System administrators should prioritize patch deployment for all affected Windows versions, particularly focusing on legacy systems that may not receive continued security support, as these systems remain vulnerable to exploitation despite the age of the vulnerability.
The broader implications of this vulnerability demonstrate the persistent challenges in legacy system security management and highlight the importance of maintaining comprehensive patch management programs. The integer overflow in media processing libraries represents a common class of vulnerabilities that can be exploited across multiple platforms, emphasizing the need for robust input validation and memory safety practices in multimedia handling components. Organizations must recognize that vulnerabilities like CVE-2009-1546 often remain relevant long after their initial discovery due to the continued presence of unpatched legacy systems in enterprise environments, making them attractive targets for persistent threat actors seeking low-hanging fruit in security defenses.