Re: [FDSA] Sort - Critical Format String Vulnerability

["Fredrick Diggle" <fdiggle () gmail com>]

Fredrick Diggle apologizes, he always forgets that exploitation is
IMPOSSIBLE if there is no how-to in phrack. Racing your own buffer is
hard Lombard so he feels your pain :(

Also how dare you accuse Diggle Sec of releasing fake vulnerabilities.
Continue down that train of thought and you are likely to find
yourself in a lawsuit sir.

Also we noted your comment about pipes and performed further analysis.
What we discovered was shocking! You are indeed correct that the
published proof of concept inadvertently exploits a previously
unpublished vulnerability it the windows command line utility. This
vulnerability allows for arbitrary command execution and is really
quite severe. We will be happy to credit you with its discovery.

On Jan 18, 2008 1:45 AM, Tonnerre Lombard <tonnerre.lombard () sygroup ch> wrote:
> Salut, Fredrick,
>
> On Thu, 17 Jan 2008 12:05:13 -0600 "Fredrick Diggle"
> <fdiggle () gmail com> wrote:
> > The following output shows a manafestation of this vulnerability:
> >
> > C:\>sort AAAA%x.%x.%x.%x
> > AAAA7c812f39.0.0.41414141The system cannot find the file specified.
>
> This is actually confirmed on Windows 2000 and XP.
>
> > This vulnerability can be trivially exploited to execute arbitrary
> > code on the computer machine.
>
> There I don't agree however, it is a simple memory reading
> vulnerability.
>
> > The following command line will use sort.exe to execute the windows
> > calculator.
> >
> > C:\>sort CALC.EXE%x%x%x%n | calc
>
> That's not very surprising since you pipe into the calculator so it is
> spawned by the shell.
>
> > Severity: Quite High
>
> There I don't agree. In theory, there should not be anything important
> in the memory of the sort process which is not already known to the
> user executing it anyway. It is clearly a bug though, and wants to be
> fixed. So congratulations to a working, though overdramatizised,
> discovered format string vulnerability.
>
>                                 Tonnerre
> --
> SyGroup GmbH
> Tonnerre Lombard
>
> Solutions Systematiques
> Tel:+41 61 333 80 33            Güterstrasse 86
> Fax:+41 61 383 14 67            4053 Basel
> Web:www.sygroup.ch              tonnerre.lombard () sygroup ch

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