Hash: SHA1

             AUSCERT External Security Bulletin Redistribution

         Vulnerability in Citrix Receiver with Online Plug-in for
             Windows could result in arbitrary code execution
                             13 September 2012


        AusCERT Security Bulletin Summary

Product:           Citrix Receiver
                   Citrix XenApp Plugin for Windows
Publisher:         Citrix
Operating System:  Windows
Impact/Access:     Execute Arbitrary Code/Commands -- Remote with User Interaction
Resolution:        Patch/Upgrade
CVE Names:         CVE-2012-4603  

Original Bulletin: 

- --------------------------BEGIN INCLUDED TEXT--------------------

Vulnerability in Citrix Receiver with Online Plug-in for Windows could result
in arbitrary code execution

Document ID: CTX134681 / Created On: Sep 12, 2012 / Updated On: Sep 12, 2012 

Severity: Medium 

Description of Problem 

A vulnerability has been identified in the Citrix Receiver with Online Plug-in 
for Windows that could potentially allow an attacker to execute arbitrary code 
on the client device in the context of the currently logged in user. 

This vulnerability is present in all versions of the Citrix Receiver for 
Windows up to and including version 3.2 and all versions of the Citrix Online 
Plug-in for Windows up to and including version 12.1. 

This vulnerability has been assigned the following CVE: 


What Customers Should Do 

This vulnerability has been addressed in the following products: 

- - The Citrix Receiver for Windows version 3.3 with Online Plug-in for Windows 
version 13.3 and later 
- - Version 12.3 of the Citrix Online Plug-in for Windows. 

Citrix recommends that customers upgrade their Citrix Receivers and Online 
Plug-ins to these versions and later. These new versions can be obtained from 
the following location: 


Mitigating Factors 

To conduct a successful exploit, an attacker would have to convince a user to 
manually lauch a specially crafted malicious file from an SMB or WebDAV 
fileserver. Deployments that prevent connections to potentially untrustworthy 
fileservers will be less exposed to this vulnerability. 


Citrix thanks Alexey Tyurin of the Digital Security Research Group 
(http://dsecrg.com/) for working with us to protect Citrix customers. 

What Citrix Is Doing 

Citrix is notifying customers and channel partners about this potential 
security issue. This article is also available from the Citrix Knowledge 
Center at http://support.citrix.com/. 

Obtaining Support on This Issue 

If you require technical assistance with this issue, please contact Citrix 
Technical Support. Contact details for Citrix Technical Support are available 
at http://www.citrix.com/site/ss/supportContacts.asp. 

Reporting Security Vulnerabilities to Citrix 

Citrix welcomes input regarding the security of its products and considers 
any and all potential vulnerabilities seriously. If you would like to report 
a security issue to Citrix, please compose an e-mail to secure@citrix.com 
stating the exact version of the product in which the vulnerability was found 
and the steps needed to reproduce the vulnerability.

This document applies to:

- - Receiver for Macintosh 
- - Receiver for Windows 
- - XenApp Plug-in for Windows (32/64 Bit)

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