A vulnerability in the way the Microsoft Windows kernel handles invalid opcodes used in DOS emulation could allow a local attacker to gain elevated privileges on a vulnerable system.
The Virtual DOS Machine (VDM) provides support for 16-bit legacy operations and applications. For instance, a VDM is started when a user executes a MS-DOS application. The Windows kernel is responsible for handling 16-bit code executed inside a VDM. There is a vulnerability in the way the Windows kernel validates memory locations allocated to a VDM. After processing an invalid opcode byte sequence, the kernel fails to validate the memory address where execution should be transferred allowing an attacker to redirect this execution to arbitrary locations in memory. Exploitation of this vulnerability could allow a local, authenticated attacker to execute arbitrary code on an affected system with kernel privileges.
Microsoft reports that this is not the same vulnerability described in MS04-011.
A local, authenticated attacker could execute arbitrary code with kernel privileges on an affected system.
This vulnerability was reported by Microsoft. Microsoft credits eEye Digital Security for discovering the vulnerability.
This document was written by Damon Morda based on information contained in the eEye Advisory.
|Date First Published:||2004-10-13|
|Date Last Updated:||2004-10-13 19:12 UTC|