Sponsored Links

Windows Hole Discovered After 17 Years

Bob2002

ULTIMATE Member
Microsoft isn't having an easy time of it these days. In addition to the unpatched hole in Internet Explorer, a now published hole in Windows allows users with restricted access to escalate their privileges to system level – and this is believed to be possible on all 32-bit versions of Windows from Windows NT 3.1 up to, and including Windows 7. While the vulnerability is likely to affect home users in only a minor way, the administrators of corporate networks will probably have their hands full this week.

The problem is caused by flaws in the Virtual DOS Machine (VDM) introduced in 1993 to support 16-bit applications (real mode applications for 8086). VDM is based on the Virtual 8086 Mode (VM86) in 80386 processors and, among other things, intercepts hardware routines such as BIOS calls. Google security team member Tavis Ormandy has found several vulnerabilities in this implementation that allow an unprivileged 16-bit program to manipulate the kernel stack of each process via a number of tricks. This potentially enables attackers to execute code at system privilege level.

Ormandy has also published a suitable exploit which functions under Windows XP, Windows Server 2003 and 2008, Windows Vista and Windows 7. When tested by the The H's associates at heise Security, the exploit opened a command prompt in the system context, which has the highest privilege level, under Windows XP and Windows 7. No patch has become available, although Ormandy reports that Microsoft was already informed of the hole in mid 2009. The developer decided to publish the information regardless because, in his opinion, there is a simple workaround: to disable the MS-DOS subsystem.

The workaround requires users to start the group policy editor and enable the "Prevent access to 16-bit applications" option in the Computer Configuration\Administrative Templates\Windows Components\Application Compatibility section. When tested with these settings by the heise Security team, the exploit no longer functioned. The settings reportedly don't cause any major compatibility problems for most users while no 16-bit applications are being used.


Read article ...
:hrmph:
 
Hmm I guess this attack wouldn't affect 64Bit installs then because, unlike the 32Bit version, 64Bit installs cannot run 16Bit applications to start with. Then again I don't know what MS did to its VDM in Win7/Vista-64Bit.. hmm.
 
Top
Cheap BIG ISPs for 100Mbps+
Community Fibre UK ISP Logo
150Mbps
Gift: None
Virgin Media UK ISP Logo
Virgin Media £22.99
132Mbps
Gift: None
Vodafone UK ISP Logo
Vodafone £24.00 - 26.00
150Mbps
Gift: None
NOW UK ISP Logo
NOW £24.00
100Mbps
Gift: None
Plusnet UK ISP Logo
Plusnet £25.99
145Mbps
Gift: £50 Reward Card
Large Availability | View All
Cheapest ISPs for 100Mbps+
Gigaclear UK ISP Logo
Gigaclear £17.00
200Mbps
Gift: None
Community Fibre UK ISP Logo
150Mbps
Gift: None
Virgin Media UK ISP Logo
Virgin Media £22.99
132Mbps
Gift: None
Hey! Broadband UK ISP Logo
150Mbps
Gift: None
Youfibre UK ISP Logo
Youfibre £23.99
150Mbps
Gift: None
Large Availability | View All
Sponsored Links
The Top 15 Category Tags
  1. FTTP (6026)
  2. BT (3639)
  3. Politics (2721)
  4. Business (2439)
  5. Openreach (2405)
  6. Building Digital UK (2330)
  7. Mobile Broadband (2146)
  8. FTTC (2083)
  9. Statistics (1901)
  10. 4G (1816)
  11. Virgin Media (1764)
  12. Ofcom Regulation (1582)
  13. Fibre Optic (1467)
  14. Wireless Internet (1462)
  15. 5G (1407)
Sponsored

Copyright © 1999 to Present - ISPreview.co.uk - All Rights Reserved - Terms  ,  Privacy and Cookie Policy  ,  Links  ,  Website Rules