Citrix Hypervisor Multiple Security Updates

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.

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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 schedule allows. The hotfixes can be downloaded from the following locations:

Citrix Hypervisor 8.1: CTX270795 – <https://support.citrix.com/article/CTX270795&gt;

Citrix Hypervisor 8.0: CTX270794 – <https://support.citrix.com/article/CTX270794&gt;

Citrix XenServer 7.1 LTSR CU2: CTX270793 – <https://support.citrix.com/article/CTX270793&gt;

Citrix XenServer 7.0: CTX270792 – <https://support.citrix.com/article/CTX270792&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
2020-04-14	Initial Publication

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