Description of Problem

An issue has been identified in AMD CPU hardware that may allow code in a guest VM to infer the value of in-memory data in other guest VMs. Although this is not an issue in the Citrix Hypervisor product itself, Citrix is releasing hotfixes that include mitigations for this hardware issue.

This issue has the following identifier:

CVE-2021-26401

Customers who are running on systems with only Intel CPUs are not affected by this AMD CPU issue.

What Customers Should Do

Citrix has released hotfixes to address this issue. Citrix recommends that affected customers install these hotfixes as their patching schedule allows. The hotfixes can be downloaded from the following locations:
Citrix Hypervisor 8.2 CU1 LTSR: CTX341439 – https://support.citrix.com/article/CTX341439
Citrix Hypervisor 8.2: CTX341440 – https://support.citrix.com/article/CTX341440
Citrix XenServer 7.1 CU2 LTSR: CTX341438 – https://support.citrix.com/article/CTX341438

What Citrix is Doing

Citrix is notifying customers and channel partners about this potential security issue through the publication of this security bulletin on the Citrix Knowledge Center at https://support.citrix.com/securitybulletins.

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.

Subscribe to Receive Alerts

Citrix strongly recommends that all customers subscribe to receive alerts when a Citrix security bulletin is created or modified at https://support.citrix.com/user/alerts.

Reporting Security Vulnerabilities to Citrix

Citrix welcomes input regarding the security of its products and considers any and all potential vulnerabilities seriously. For details on our vulnerability response process and guidance on how to report security-related issues to Citrix, please see the following webpage: https://www.citrix.com/about/trust-center/vulnerability-process.html.

Disclaimer

This document is provided on an "as is" basis and does not imply any kind of guarantee or warranty, including the warranties of merchantability or fitness for a particular use. Your use of the information on the document is at your own risk. Citrix reserves the right to change or update this document at any time. Customers are therefore recommended to always view the latest version of this document directly from the Citrix Knowledge Center.

Changelog

Date	Change
2022-03-08	Initial Publication

Citrix Hypervisor Security Update

Description of Problem

What Customers Should Do

What Citrix is Doing

Obtaining Support on This Issue

Subscribe to Receive Alerts

Reporting Security Vulnerabilities to Citrix

Disclaimer

Changelog

Vulmon Search

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