Re: [FDSA] Sort - Critical Format String Vulnerability

["Joey Mengele" <joey.mengele () hushmail com>]

Dear Lombard Retard,

Excellent analysis, except it is completely wrong LOLOLOLOL.

Try %n.

J

"Gratitude is a sickness suffered by dogs." - Gadi Evron

On Fri, 18 Jan 2008 02:45:41 -0500 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
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