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                             Luigi Auriemma

Application:  Siemens Tecnomatix FactoryLink
              http://www.usdata.com/sea/FactoryLink/en/p_nav1.html
              http://www.plm.automation.siemens.com/en_us/products/tecnomatix/production_management/factorylink/index.shtml
Versions:     <= 8.0.1.1473
Platforms:    Windows
Bug:          memory corruption
Exploitation: remote, versus server
Date:         21 Mar 2011 (found 02 Jan 2011)
Author:       Luigi Auriemma
              e-mail: aluigi@autistici.org
              web:    aluigi.org


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1) Introduction
2) Bug
3) The Code
4) Fix


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===============
1) Introduction
===============


From vendor's website:
"Siemens FactoryLink monitors, supervises, and controls industrial
processes by enabling customers to perfect their processes and
products. Built on an advanced open architecture, FactoryLink delivers
the highest performance and flexibility to customers building vertical
applications in a wide range of industries.
Highly scaleable, FactoryLink can be used to build virtually any size
application, from the simplest Human-Machine Interface (HMI) systems to
the most complex and demanding Supervisory Control and Data Acquisition
(SCADA) systems."


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2) Bug
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vrn.exe is a server listening on port 7579 when a project is started.

There is a particular function used to parse the text fields located in
the strings of the opcode 10.
It copies the string delimited by a ';' or a space in the stack buffer
provided by the callee function causing a stack overflow that allows a
certain control on the code flow (for example the changing of the lower
8bit of the return address or another exception).


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===========
3) The Code
===========


http://aluigi.org/poc/factorylink_3.zip

  nc SERVER 7579 < factorylink_3.dat


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4) Fix
======


No fix.

UPDATE 25 Mar 2011:
version 802.82


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