CVE-2005-0803 in Windows
Summary
by MITRE
The GetEnhMetaFilePaletteEntries API in GDI32.DLL in Windows 2000 allows remote attackers to cause a denial of service (application crash) via a crafted Enhanced Metafile (EMF) file that causes invalid (1) end, (2) emreof, or (3) palent offsets to be used, aka "Enhanced Metafile Vulnerability."
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Analysis
by VulDB Data Team • 01/03/2025
The CVE-2005-0803 vulnerability represents a critical denial of service flaw within the Windows 2000 operating system's graphics subsystem, specifically affecting the GetEnhMetaFilePaletteEntries API function in the GDI32.DLL component. This vulnerability falls under the broader category of buffer overflow conditions and memory corruption issues that have historically plagued Microsoft Windows operating systems. The flaw manifests when the system processes specially crafted Enhanced Metafile (EMF) files, which are vector graphics formats used for storing graphical information in windows environments. The vulnerability is particularly concerning as it can be exploited remotely, allowing attackers to trigger application crashes without requiring local system access or user interaction.
The technical exploitation of this vulnerability occurs through manipulation of specific EMF file structures that contain invalid offset values for the end, emreof, or palent entries within the Enhanced Metafile format. These offsets are critical pointers that define where various elements of the metafile data structure begin and end, and when they contain malformed values, the GetEnhMetaFilePaletteEntries function fails to properly validate these offsets before attempting to access memory locations. The function essentially attempts to read palette entries from memory locations that are either invalid or outside the bounds of the allocated memory space, leading to memory access violations that result in application crashes. This behavior aligns with CWE-125, which describes out-of-bounds read conditions, and represents a classic example of improper input validation in system-level APIs. The vulnerability demonstrates how improper bounds checking in graphics processing functions can lead to complete system instability.
The operational impact of CVE-2005-0803 extends beyond simple application crashes to potentially affect entire system stability, particularly in environments where Windows 2000 systems are deployed. When exploited successfully, this vulnerability can cause denial of service conditions that may require system rebooting to resolve, disrupting business operations and potentially providing attackers with opportunities for further exploitation. The vulnerability is particularly dangerous in server environments where continuous availability is critical, as a successful attack could result in service interruptions that impact multiple users or applications. From an attack methodology perspective, this vulnerability maps to the MITRE ATT&CK framework's T1499.004 technique, which covers network denial of service attacks, and represents a form of privilege escalation through system resource exhaustion. The fact that this vulnerability can be triggered through remote file processing means that attackers could potentially deliver malicious EMF files through email attachments, web downloads, or file sharing mechanisms without requiring any special privileges or user interaction.
Mitigation strategies for CVE-2005-0803 should focus on both immediate remediation and long-term security hardening measures. Microsoft addressed this vulnerability through security updates that improved input validation within the GetEnhMetaFilePaletteEntries function and enhanced the robustness of EMF file processing. Organizations should ensure that all Windows 2000 systems are patched with the appropriate security updates and consider implementing additional protective measures such as restricting access to EMF file processing capabilities, implementing file type filtering mechanisms, and deploying network-based intrusion detection systems that can identify suspicious EMF file patterns. Security professionals should also consider implementing application whitelisting policies that restrict which applications can process EMF files, thereby reducing the attack surface. The vulnerability serves as a reminder of the importance of proper input validation in system-level APIs and demonstrates how seemingly minor flaws in graphics processing components can have significant security implications, particularly in legacy systems that continue to operate in enterprise environments despite their age and known vulnerabilities.