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                             CERT-Renater

                 Note d'Information No. 2020/VULN197
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DATE                : 15/04/2020

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running Citrix Hypervisor versions 8.1,
                                               8.0,
                         XenServer versions 7.1 LTSR 7.0, 7.0.

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https://support.citrix.com/article/CTX270837
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CTX270837


Citrix Hypervisor Multiple Security Updates
Security Bulletin | Medium | Created: 14 Apr 2020 | Modified: 14 Apr 2020


Applicable Products

    Citrix Hypervisor 8.1
    Citrix Hypervisor 8.0
    XenServer 7.1 LTSR Cumulative Update 2
    XenServer 7.0


Description of Problem

Several issues have been identified within Citrix Hypervisor, which
could, if exploited, allow:

    privileged code in a PV guest VM to read a single uninitialized 4kB
page of memory (that may contain data left by a previous VM)

    privileged code in a guest VM to cause the host to crash


These vulnerabilities affect all currently supported versions of Citrix
Hypervisor up to and including Citrix Hypervisor 8.1.

These issues have the following identifiers:

    CVE-2020-11740
    CVE-2020-11741
    CVE-2020-11742
    CVE-2020-11743

Note that support for PV guests was removed in Citrix Hypervisor 8.1.
The provided hotfix for Citrix Hypervisor 8.1 does address both issues
but customers should not assume that Citrix will address any future
security issues related to PV guests running on Citrix Hypervisor 8.1.


What Customers Should Do

Hotfixes have been released to address these issues. Citrix recommends
that affected customers install these hotfixes as their patching
schedule allows. The hotfixes can be downloaded from the following
locations:

Citrix Hypervisor 8.1: CTX270795 –
https://support.citrix.com/article/CTX270795

Citrix Hypervisor 8.0: CTX270794 –
https://support.citrix.com/article/CTX270794

Citrix XenServer 7.1 LTSR CU2: CTX270793 –
https://support.citrix.com/article/CTX270793

Citrix XenServer 7.0: CTX270792 –
https://support.citrix.com/article/CTX270792


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


Changelog

Date            Change
2020-04-14 	Initial Publication


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+ CERT-RENATER        | tel : 01-53-94-20-44            +
+ 23/25 Rue Daviel    | fax : 01-53-94-20-41            +
+ 75013 Paris         | email:cert@support.renater.fr   +
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