[Infowarrior] - Researchers unpick Vista kernel protection

[Richard Forno]

Researchers unpick Vista kernel protection
>From boot kit to 'root kit'
By John Leyden → More by this author
Published Wednesday 4th April 2007 19:01 GMT
http://www.theregister.co.uk/2007/04/04/vbootkit/

Security researchers have found a way to subvert the load-up procedure for
Windows Vista and bypass its code-signing security checks.

Indian researchers Nitin and Vipin Kumar of NV labs have developed a tool
called VBoot kit, a custom boot sector loader, which launches from a CD.
Once loaded, the tool allows hackers to make system changes on pre-release
versions of Vista, something that only Microsoft-signed code is supposed to
be able to do.

Vista's booting process fails to check that every previously loaded
component is kosher. The Kumar brothers exploited this design "feature" to
craft their proof-of-concept code. VBoot kit can copy itself to a section of
memory before Vista boots, so bypassing restrictions that should prevent
unsigned code running with system (kernel) privileges.

The code, developed on a beta version of Vista, was demonstrated during a
presentation at last week's Black Hat conference in Amsterdam.

Heise Security reports that a complex debugging process, involving finding
the memory areas vBoot kit needed to load onto, was needed to get the
exploit to work. Adapting the code to work on later versions of Vista would
involve a similar, time-consuming process.

The attack does not lend itself immediately toward the creation of root kits
that work on the final Vista build. Even so, the Kumars' work illustrates
fundamental design weaknesses the researchers reckon can only be fully
addressed by using TPM (Trusted Platform Module) hardware to stop unsigned
program code from being executed. ®