Citrix Hypervisor Security Bulletin for CVE-2023-20569, CVE-2023-34319 and CVE-2022-40982

Description of Problem

An issue has been discovered in Citrix Hypervisor 8.2 CU1 LTSR that may allow malicious, privileged code in a guest VM to cause the host to crash.
This issue has the following identifier:

• CVE-2023-34319

In addition, Intel has disclosed a security issue affecting certain Intel CPUs that may allow malicious code in a guest VM to infer the contents of vector registers belonging to other processes running on the same CPU core.  Although this is not an issue in the Citrix Hypervisor product itself, we have included product changes and updated microcode to mitigate this CPU hardware issue.
This issue has the following identifier:

• CVE-2022-40982

In addition, AMD has disclosed a security issue affecting AMD CPUs that may allow malicious code in a guest VM to infer the contents of memory belonging to other processes running on the same CPU core.  Although this is not an issue in the Citrix Hypervisor product itself, we have included product changes and updated microcode to mitigate this CPU hardware issue.
This issue has the following identifier:

• CVE-2023-20569

Mitigating Factors

CVE-2022-40982 only affects Citrix Hypervisor when running on Intel CPUs with Skylake Server, Coffee Lake Server, Cooper Lake Server or Ice Lake Server microarchitectures; it does not affect Citrix Hypervisor when running on other supported CPUs.

CVE-2023-20569 only affects Citrix Hypervisor when running on AMD CPUs with Zen 3 or Zen 4 microarchitectures.  It does not affect Citrix Hypervisor when running on other supported CPUs provided that all previous updates have been applied.

 

What Customers Should Do

We have released hotfixes to address these issues. We recommend that affected customers install these hotfixes and follow the instructions in the linked articles as their update schedule permits.  The hotfixes can be downloaded from the following locations:

CTX564360 – https://support.citrix.com/article/CTX564360  
CTX569269 – https://support.citrix.com/article/CTX569269  
CTX570473 – https://support.citrix.com/article/CTX570473 ​​​​​​​

Note that there is not a one-to-one correlation between these hotfixes and the addressed issues; we recommend that you always apply all three hotfixes.

What Citrix Is Doing 

We are 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
2023-08-08	Initial Publication