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             AUSCERT External Security Bulletin Redistribution

                Citrix XenServer Multiple Security Updates
                              4 December 2017


        AusCERT Security Bulletin Summary

Product:           Citrix XenServer
Publisher:         Citrix
Operating System:  Xen
Impact/Access:     Execute Arbitrary Code/Commands -- Existing Account
                   Increased Privileges            -- Existing Account
                   Denial of Service               -- Existing Account
                   Access Confidential Data        -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-17045 CVE-2017-17044 CVE-2017-15592

Reference:         ESB-2017.3002

Original Bulletin: 

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Citrix XenServer Multiple Security Updates

Security Bulletin | High | Created: 01 Dec 2017 | Modified: 01 Dec 2017

Applicable Products

    XenServer 7.2
    XenServer 7.1 LTSR Cumulative Update 1
    XenServer 7.1
    XenServer 7.0
    XenServer 6.5
    XenServer 6.2.0
    XenServer 6.0.2

Description of Problem

A number of security vulnerabilities have been identified in Citrix XenServer 
that may allow a malicious administrator of an HVM guest VM to compromise the 

These vulnerabilities affect all currently supported versions of Citrix 
XenServer up to and including Citrix XenServer 7.2.

The following vulnerabilities have been addressed:

    CVE-2017-7980: code execution via overflow in Cirrus Logic emulation
    CVE-2017-15592: Incorrect handling of self-linear shadow mappings with 
    translated guests
    CVE-2017-17044: Infinite loop due to missing PoD error checking
    CVE-2017-17045: Missing p2m error checking in PoD code

Mitigating Factors

Customers without HVM guests (i.e. PV guests only) are not affected by these 

What Customers Should Do

Hotfixes have been released to address these issues. Citrix strongly recommends
that affected customers install these hotfixes as soon as possible. The
hotfixes can be downloaded from the following locations:

Citrix XenServer 7.2: CTX229541 – https://support.citrix.com/article/CTX229541
and CTX230161 – https://support.citrix.com/article/CTX230161

Citrix XenServer 7.1 LTSR CU1: CTX229540 – 
https://support.citrix.com/article/CTX229540 and CTX230160 – 

Citrix XenServer 7.1 LTSR: CTX229545 – 
https://support.citrix.com/article/CTX229545 and CTX230159 – 

Citrix XenServer 7.0: CTX229539 – https://support.citrix.com/article/CTX229539
and CTX229544 – https://support.citrix.com/article/CTX229544

Citrix XenServer 6.5 SP1: CTX229543 – 

Citrix XenServer 6.2 SP1: CTX229096 – 

Citrix XenServer 6.0.2 Common Criteria: CTX229095 – 

Customers using the LivePatching feature of Citrix XenServer will not need to 
reboot servers to apply this hotfix but HVM guest VMs must either be rebooted
or migrated to a server with the hotfix already applied for the hotfix to be
fully effective.

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  https://www.citrix.com/support/open-a-support-case.html. 

Reporting Security Vulnerabilities

Citrix welcomes input regarding the security of its products and considers
any and all potential vulnerabilities seriously. For guidance on how to 
report security-related issues to Citrix, please see the following document: 
CTX081743 – Reporting Security Issues to Citrix

Date  			Change
1st December 2017 	Initial publishing

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