Citrix Hypervisor Security Update

Description of Problem

A number of vulnerabilities have been found in Citrix Hypervisor (formerly Citrix XenServer) that may:

i. Allow the host to be compromised by privileged code in a PV guest VM,

ii. allow unprivileged code in a HVM guest VM to cause that guest to crash and

iii. under certain conditions, allow an HVM guest VM to cause the host to eventually run out of memory.

These issues have the following identifiers:

• CVE-2019-19580

• CVE-2019-19583

• CVE-2019-19577

In addition, this hotfix contains updated microcode that addresses an issue in specific Intel CPU hardware that may allow malicious unprivileged code within a guest VM to compromise that guest VM.

This issue has the following identifier:

• CVE-2019-14607

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

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Mitigating Factors

Customers running only HVM workloads are not affected by the host compromise issue.

Customers who are not running on AMD hardware, or who do not use PCI Passthrough functionality, are not affected by the memory exhaustion issue.

Not all Intel CPUs are affected by the Intel CPU hardware issue. Details of which CPUs are affected can be found at: <https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00317.html&gt;.

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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: CTX263620 – <https://support.citrix.com/article/CTX263620&gt;

Citrix XenServer 7.6: CTX263619 - <https://support.citrix.com/article/CTX263619&gt;

Citrix XenServer 7.1 LTSR CU2: CTX263618 - <https://support.citrix.com/article/CTX263618&gt;

Citrix XenServer 7.0: CTX263617 - <https://support.citrix.com/article/CTX263617&gt;

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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/&gt;_.

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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&gt;_.

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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

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Changelog

Date	Change
11th December 2019	Initial Publication

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