RE: Citrix application breakout - take care of Microsoft calculator

["Erik Soosalu" <eriks () nationalfastfreight com>]

Once you're  in Notepad, File->Open, browse to Windows/system32, find cmd.exe right click and open and you have a 
command prompt on the box.  Of course, your could specify any UNC and get a file to load from wherever you want.  Not 
sure what the actual run permissions would be....
 
Erik
 
 

________________________________

From: listbounce () securityfocus com on behalf of Stefan Gora
Sent: Fri 3/7/2008 6:13 AM
To: pen-test () securityfocus com
Subject: Citrix application breakout - take care of Microsoft calculator



Dear all,

I'm not shure if the following issue is already known or exciting,
nevertheless the following attack vector found during a penetration test
might be interesting:

A customer has built a Citrix environment for a partner company to
provide access to a specific application. This application was intended
to be the only application accessible for this partner. It was possible
to get a remote task manager with CRTL-F3, but no other way of
interacting with the Citrix Server (e.g. through printing or so).

Unfortunately they have integrated Microsoft's calculator into the
application. A bad idea - guess why ;-).

Using the calculator you are able to do funny stuff: Open the calculator
and click "info". Klick on the licence agreement and here you go, you
have got an editor. With this you can use "open file" and browse the
server, find for example Word and rightclick on "Open" - Word is
running, and all other applications which you like as well ...

I think this can easily be fixed using more restrictive file
permissions, but I thought maybe some of you might find this information
useful.

Stefan

--
--------------------------------------------------------
Identity Management Symposium 22.-23.04.2008 KA/Ettlingen
http://www.identity-management-symposium.de <http://www.identity-management-symposium.de/> 
--------------------------------------------------------

Stefan Gora
Security Consultant

Secorvo Security Consulting GmbH
Ettlinger Strasse 12-14, D-76137 Karlsruhe
Tel. +49 721 255171-302, Fax +49 721 255171-100
stefan.gora () secorvo de, http://www.secorvo.de <http://www.secorvo.de/> 
PGP: 5EAD 34FE F3C1 0FEB  058F 4DD0 E6B3 FF4A

Mannheim HRB 108319, Geschaeftsfuehrer: Dirk Fox

------------------------------------------------------------------------
This list is sponsored by: Cenzic

Need to secure your web apps NOW?
Cenzic finds more, "real" vulnerabilities fast.
Click to try it, buy it or download a solution FREE today!

http://www.cenzic.com/downloads
------------------------------------------------------------------------





------------------------------------------------------------------------
This list is sponsored by: Cenzic

Need to secure your web apps NOW?
Cenzic finds more, "real" vulnerabilities fast.
Click to try it, buy it or download a solution FREE today!

http://www.cenzic.com/downloads
------------------------------------------------------------------------