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             AUSCERT External Security Bulletin Redistribution

                Citrix XenServer Multiple Security Updates
                             14 November 2012


        AusCERT Security Bulletin Summary

Product:           Citrix XenServer
Publisher:         Citrix
Operating System:  Windows
Impact/Access:     Denial of Service -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2012-4557 CVE-2012-4539 CVE-2012-4538
                   CVE-2012-4537 CVE-2012-4536 CVE-2012-4535

Original Bulletin: 

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Citrix XenServer Multiple Security Updates

Document ID: CTX135458 / Created On: 13-Nov-2012   /  Updated On: 13-Nov-2012

Severity: Medium

Description of Problem

A number of security vulnerabilities have been identified in Citrix XenServer.
These vulnerabilities affect all currently supported versions of Citrix
XenServer up to and including version 6.1.

The following denial of service vulnerabilities have been addressed:
 Timer overflow DoS vulnerability (CVE-2012-4535)
 pirq range check DoS vulnerability (CVE-2012-4536)
 Memory mapping failure DoS vulnerability (CVE-2012-4537)
 Unhooking empty PAE entries DoS vulnerability (CVE-2012-4538)
 Grant table hypercall infinite loop DoS vulnerability (CVE-2012-4539)
 XENMEM_add_to_physmap DoS vulnerability (CVE-2012-4557)

What Customers Should Do

Hotfixes have been released to address these issues in all supported versions
and update levels of Citrix XenServer. Citrix strongly recommends that
customers using Citrix XenServer identify and apply the hotfixes that relate to
their deployed versions:

Citrix XenServer 6.1:

Citrix XenServer 6.0.2:

Citrix XenServer 6.0.2 CC: 
Customers using Citrix XenServer 6.0.2 in the Common Criteria evaluated
configuration should apply the following hotfixes:

Please note that the Common Criteria Target Of Evaluation (TOE) is not affected
by the vulnerabilities disclosed in this bulletin.

Citrix XenServer 6.0.0:

Citrix XenServer 5.6 Service Pack 2:

Citrix XenServer 5.6 Feature Pack 1:

Citrix XenServer 5.6:

Citrix XenServer 5.6 CC:
Customers using Citrix XenServer 5.6 in the Common Criteria evaluated
configuration should apply the following hotfixes:

Please note that the Common Criteria Target Of Evaluation (TOE) is not affected
by the vulnerabilities disclosed in this bulletin.

Citrix XenServer 5.5 Update 2:

Citrix XenServer 5.0 Update 3:

Customers using Citrix CloudPlatform, previously known as Citrix CloudStack,
that use XenServer are recommended to apply the hotfix relevant to their
version of XenServer.

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:

XenServer 5.0 Update 3
XenServer 5.5
XenServer 5.6
XenServer 5.6 Common Criteria
XenServer 5.6 FP 1
XenServer 5.6 SP 2
XenServer 6.0
XenServer 6.0.2
XenServer 6.0.2 Common Criteria
XenServer 6.1.0

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