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

                             CERT-Renater

                 Note d'Information No. 2019/VULN352

_____________________________________________________________________

DATE                : 06/11/2019

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running Citrix Hypervisor versions 8.0,
                       Citrix XenServer versions 7.6, 7.1 LTSR, 7.0.

=====================================================================
https://support.citrix.com/article/CTX263477
_____________________________________________________________________

CTX263477
Citrix Hypervisor Security Update

Created: 31 Oct 2019 | Modified: 31 Oct 2019


    Citrix Hypervisor 8.0
    XenServer 7.6
    XenServer 7.1 LTSR Cumulative Update 2
    XenServer 7.0


Description of Problem

A number of vulnerabilities have been found in Citrix Hypervisor
(formerly Citrix XenServer) that allow the host to be compromised
by:

i. Privileged code in a guest VM that has been assigned a PCI
passthrough device

ii. Privileged code in a PV guest VM

iii. Unprivileged code in a 32-bit PV guest VM



These vulnerabilities have the following identifiers:

• CVE-2019-18420

• CVE-2019-18421

• CVE-2019-18424

• CVE-2019-18425

These issues affect all currently supported versions of Citrix
Hypervisor up to and including Citrix Hypervisor 8.0.


Mitigating Factors

Customers running only HVM workloads and not making use of PCI
passthrough functionality are not affected by these issues.  Note
that all Microsoft Windows VMs run as HVM VMs.


What Customers Should Do

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

Citrix Hypervisor 8.0:

    CTX262555 -  https://support.citrix.com/article/CTX262555

    CTX258428 -  https://support.citrix.com/article/CTX258428

Citrix XenServer 7.6:

    CTX262554 - https://support.citrix.com/article/CTX262554

    CTX258425 - https://support.citrix.com/article/CTX258425

Citrix XenServer 7.1 LTSR CU2:

    CTX262553 - https://support.citrix.com/article/CTX262553

    CTX258424 - https://support.citrix.com/article/CTX258424

Citrix XenServer 7.0:

    CTX258417 - https://support.citrix.com/article/CTX258417

    CTX258423 - https://support.citrix.com/article/CTX258423


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
31st October 2019       Initial publication

=========================================================
+ 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   +
=========================================================