Date: Wed, 30 Apr 2014 18:37:46 -0400
From: Mike Cramer <mike.cramer@...look.com>
To: "'Alton Blom'" <altonius@...il.com>
Cc: fulldisclosure@...lists.org, 'Stefan Kanthak' <stefan.kanthak@...go.de>
Subject: Re: [FD] Beginners error: iTunes for Windows runs rogue program
	C:\Program.exe when opening associated files

I bring this up because this has been an extreme sore point on our network and our security group utilizing the Nessus plugin. Attempting to explain to them that UAC and the elevated privilege requirement makes this a non-issue is falling on deaf ears to those that blindly follow what the scanner states. There’s little to no wiggle room as there’s very little information on this that’s out there other than “OMG THE SKY IS FALLING”.

 

Even Tenable’s own blog post, http://www.tenable.com/sc-report-templates/microsoft-windows-unquoted-service-path-enumeration, shows them “exploiting this vulnerability” by using an elevated command prompt using an elevated privilege token.

 

There are software vendors that will never ‘fix’ their software. A great example being the IDT Audio driver released by Dell for their Latitude 6520 series of laptops creates a service called “AESTFilters” which installs an unquoted service path in C:\Program Files.

 

Juniper Network Connect VPN Client 7.1.7 also creates a service with an unquoted service path string.

 

The only ‘resolution’ is an active mitigation which continuously evaluates all Windows systems on a network to search remotely for unquoted service paths.

 

There exist a couple of scripts that will troll the registry services key for these issues, but Windows uses the same key to load kernel drivers, differentiating each service via a “Type” parameter. (http://support.microsoft.com/kb/103000) I’m not sure how much faith you place in an active network application remotely modifying an extremely critical registry sub key on a thousand node network and hope it doesn’t accidentally place a quote in the wrong location and prevents Windows from starting for your entire organization. It seems the risk there is significantly greater than any benefit provided by resolving this issue.

 

Many operational security groups are placing the burden of resolution on IT operations departments (My organization is not the only one to go through this) rather than application vendors.

 

 

 

From: Alton Blom [mailto:altonius@...il.com] 
Sent: Wednesday, April 30, 2014 18:18
To: Mike Cramer
Cc: Stefan Kanthak; fulldisclosure@...lists.org
Subject: Re: [FD] Beginners error: iTunes for Windows runs rogue program C:\Program.exe when opening associated files

 

Hi Mike,

It's probalby better seen as a way of keeping persistence on a machine than a full-blown exploit.

Alton(ius)
altonblom.com <http://altonblom.com> 

@altonius_au

 

On Thu, May 1, 2014 at 8:05 AM, Mike Cramer <mike.cramer@...look.com <mailto:mike.cramer@...look.com> > wrote:

I would like to know how this is a vulnerability.

In order to write to the root of C:\, you need elevated privileges in
Windows. Once someone gains elevated access, what does creating
"C:\program.exe" offer them that they couldn't otherwise obtain?

I have never actually seen malware take advantage of this, often times
leveraging Kernel hooks and driver loading.

It is unintended behavior, yes; but I'd consider it hardly a vulnerability.

-Mike


-----Original Message-----
From: Fulldisclosure [mailto:fulldisclosure-bounces@...lists.org <mailto:fulldisclosure-bounces@...lists.org> ] On Behalf
Of Alton Blom
Sent: Wednesday, April 30, 2014 17:51
To: Stefan Kanthak
Cc: fulldisclosure@...lists.org <mailto:fulldisclosure@...lists.org> 
Subject: Re: [FD] Beginners error: iTunes for Windows runs rogue program
C:\Program.exe when opening associated files

Hi Stefan,

SANS had a good post on this a few years ago (
https://isc.sans.edu/diary/Help+eliminate+unquoted+path+vulnerabilities/1446
4),
which led to large number of services on windows machines with unquoted
paths being discovered and fixed.  At that time I discovered that Windows
Defender on Windows 7 had a problem like yours and reported it to Microsoft.
It took quite a while to get them to recognise it as a vulnerability, but it
eventually led to
https://technet.microsoft.com/en-us/library/security/ms13-058.aspx being
released and Windows Defender being updated.

At the same time I asked Tenable to create a plugin for Nessus that detects
vulnerable services which they quickly released (plugin 63155).  This in
turn led to a second round of vulnerable services being detected and patched
by vendors.

Also it's worth noting that OSVDB track these types of Vulns as
"Authentication Required, Not a Vulnerability"

Alton(ius)
altonblom.com <http://altonblom.com> 


On Thu, May 1, 2014 at 5:02 AM, Stefan Kanthak
<stefan.kanthak@...go.de <mailto:stefan.kanthak@...go.de> >wrote:

> Hi @ll,
>
> the current version of iTunes for Windows (and of course older
> versions
> too) associates the following vulnerable command lines with some of
> the supported file types/extensions:
>
> daap=C:\Program Files (x86)\iTunes\iTunes.exe /url "%1"
> itls=C:\Program Files (x86)\iTunes\iTunes.exe /url "%1"
> itms=C:\Program Files (x86)\iTunes\iTunes.exe /url "%1"
> itmss=C:\Program Files (x86)\iTunes\iTunes.exe /url "%1"
> itpc=C:\Program Files (x86)\iTunes\iTunes.exe /url "%1"
> itsradio=C:\Program Files (x86)\iTunes\iTunes.exe /url "%1"
> iTunes=C:\Program Files (x86)\iTunes\iTunes.exe /url "%1"
> iTunes.AssocProtocol.daap=C:\Program Files (x86)\iTunes\iTunes.exe
> /url "%1"
> iTunes.AssocProtocol.itls=C:\Program Files (x86)\iTunes\iTunes.exe
> /url "%1"
> iTunes.AssocProtocol.itms=C:\Program Files (x86)\iTunes\iTunes.exe
> /url "%1"
> iTunes.AssocProtocol.itmss=C:\Program Files (x86)\iTunes\iTunes.exe
> /url"%1"
> iTunes.AssocProtocol.itpc=C:\Program Files (x86)\iTunes\iTunes.exe
> /url "%1"
> iTunes.AssocProtocol.pcast=C:\Program Files (x86)\iTunes\iTunes.exe
> /url"%1"
> itunesradio=C:\Program Files (x86)\iTunes\iTunes.exe /url "%1"
> pcast=C:\Program Files (x86)\iTunes\iTunes.exe /url "%1"
>
>
> The command line registered under
>
> [HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Media\iTunes\shell\open\command]
> @="C:\Program Files\iTunes\iTunes.exe"
>
> shows the same beginners error too: an unquoted pathname allows the
> execution of the rogue programs "C:\Program.exe" or "C:\Program Files.exe"
> instead of the intended executable.
>
>
> From <http://msdn.microsoft.com/library/cc144175.aspx>
> or <http://msdn.microsoft.com/library/cc144101.aspx>:
>
> | Note: If any element of the command string contains or might contain
>         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | spaces, it must be enclosed in quotation marks. Otherwise, if the
>   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | element contains a space, it will not parse correctly. For instance,
> | "My Program.exe" starts the application properly. If you use My
> | Program.exe without quotation marks, then the system attempts to
> | launch My with Program.exe as its first command line argument. You
> | should always use quotation marks with arguments such as "%1" that
> | are expanded to strings by the Shell, because you cannot be certain
> | that the string will not contain a space.
>
>
> "Long" filenames containing spaces exist for about 20 years in Windows.
> It's REALLY time that every developer and every QA engineer knows how
> to handle them properly.
>
>
> If you detect such silly bugs: report them and get them fixed.
> If the vendor does not fix them: trash the trash!
>
>
> JFTR: this bugs only exists since Microsoft "masks" it.
>       See <http://msdn.microsoft.com/library/ms682425.aspx> for this
>       well-known idiosyncrasy:
>
> | For example, consider the string "c:\program files\sub dir\program
name".
> | This string can be interpreted in a number of ways.
> | The system tries to interpret the possibilities in the following order:
> | c:\program.exe files\sub dir\program name c:\program files\sub.exe
> | dir\program name c:\program files\sub dir\program.exe name
> | c:\program files\sub dir\program name.exe
>
>       Without this kludge this beginners error would get caught upon
>       the very first use of any of these command lines.
>
>
> Since every user account created during Windows setup has
> administrative rights every user owning such an account can create the
> rogue program, resulting in a privilege escalation.
>
> JFTR: no, the "user account control" is not a security boundary!
>
>
> regards
> Stefan Kanthak
>
>
> PS: for static detection of these silly beginners errors download and
>     run <http://home.arcor.de/skanthak/download/SLOPPY.CMD>
>
>     To catch all instances of this beginners error download
>     <http://home.arcor.de/skanthak/download/SENTINEL.CMD>,
>     <http://home.arcor.de/skanthak/download/SENTINEL.DLL> and
>     <http://home.arcor.de/skanthak/download/SENTINEL.EXE>, then read
>     and run SENTINEL.CMD
>
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