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Luigi Auriemma

Application: GO-Global for Windows
http://www.graphon.com/products/GO-G...rWindows.shtml
Versions: <= 3.1.0.3270
Platforms: Server: Windows
Clients: Windows, Solaris, HP-UX, IBM AIX and Linux
Java version not vulnerable
Bug: buffer-overflow
Exploitation: remote, versus server and client
Date: 02 Nov 2005
Author: Luigi Auriemma
e-mail: aluigi@autistici.org
web: http://aluigi.altervista.org


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


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


GO-Global for Windows is a server-based thin-client solution.
It allows users to run 32-bit Windows applications remotely from a
server, the application runs entirely on the server but is displayed on
the client.


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2) Bug
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After the initial handshake where is specified the type of encryption
to use (_USERSA_), the application uses 16 bit fields for specifying
the length of the subsequent data blocks.
Both the client and the server use a small buffer which leads to a
buffer-overflow if an attacker uses a data block longer than its size.
Both server and clients are vulnerables.


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


For testing the "GO-Global for Windows" server:
http://aluigi.altervista.org/poc/ggwbof.zip

For testing the "GO-Global for Windows" clients:
http://aluigi.altervista.org/poc/ggwbofc.zip


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4) Fix
======


Version 3.1.0.3281


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---
Luigi Auriemma
http://aluigi.altervista.org