-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2013.0571
                     Citrix XenServer Security Update
                               23 April 2013

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Citrix XenServer
Publisher:         Citrix Systems
Operating System:  UNIX variants (UNIX, Linux, OSX)
Impact/Access:     Denial of Service -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2013-1917  

Reference:         ESB-2013.0557

Original Bulletin: 
   http://support.citrix.com/article/CTX137478

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

Citrix XenServer Security Update

Document ID: CTX137478

Created On: Apr 18, 2013

Updated On: Apr 18, 2013

Severity: Low

Description of Problem

A security vulnerability has been identified in Citrix XenServer. This 
vulnerability allows an unprivileged user of a guest VM to crash the host.

The vulnerability is identified as:

    * CVE-2013-1917: Xen PV DoS vulnerability with SYSENTER

Mitigating Factors

The vulnerability can only be exploited from PV guest VMs running on Intel 
CPUs.

What Customers Should Do

Hotfixes have been released to address this issue. Citrix recommends that 
affected customers install the relevant hotfix, which can be downloaded from 
the following locations:

Citrix XenServer 6.1:
CTX137487 - Hotfix XS61E019 - For XenServer 6.1.0

Citrix XenServer 6.0.2:
CTX137486 - Hotfix XS602E022 - For XenServer 6.0.2

Citrix XenServer 6.0.0:
CTX137484 - Hotfix XS60E028 - For XenServer 6.0

Citrix XenServer 5.6 Service Pack 2:
CTX137483 - Hotfix XS56ESP2027 - For XenServer 5.6 Service Pack 2

Citrix XenServer 5.6 Feature Pack 1:
CTX137482 - Hotfix XS56EFP1017 - For XenServer 5.6 Feature Pack 1

Citrix XenServer 5.6:
CTX137481 - Hotfix XS56E018 - For XenServer 5.6

Citrix XenServer 5.5 Update 2:
CTX137480 - Hotfix XS55EU2016 - For XenServer 5.5 Update 2

Citrix XenServer 5.0 Update 3:
CTX137479 - Hotfix XS50EU3016 - For XenServer 5.0 Update 3

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

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        http://www.auscert.org.au/render.html?cid=1980

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
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=kNO3
-----END PGP SIGNATURE-----