Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
6DescriptionCVE.org
The kernel in Microsoft Windows NT 3.1 through Windows 7, including Windows 2000 SP4, Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista Gold, SP1, and SP2, and Windows Server 2008 Gold and SP2, when access to 16-bit applications is enabled on a 32-bit x86 platform, does not properly validate certain BIOS calls, which allows local users to gain privileges by crafting a VDM_TIB data structure in the Thread Environment Block (TEB), and then calling the NtVdmControl function to start the Windows Virtual DOS Machine (aka NTVDM) subsystem, leading to improperly handled exceptions involving the #GP trap handler (nt!KiTrap0D), aka "Windows Kernel Exception Handler Vulnerability."
AnalysisAI
The Windows kernel from NT 3.1 through Windows 7 improperly validates BIOS calls on 32-bit x86 platforms with 16-bit application support enabled, allowing local users to gain SYSTEM privileges and bypass UAC.
Technical ContextAI
When 16-bit application support is enabled on 32-bit Windows, the kernel fails to properly validate certain BIOS interrupt calls. A local attacker can craft a malicious 16-bit application that exploits this validation gap to execute code with ring-0 privileges.
RemediationAI
Apply Microsoft security update. Disable 16-bit application support via Group Policy (NTVDM subsystem) on systems that don't require legacy application compatibility.
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External POC / Exploit Code
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