Citrix Hypervisor Security Bulletin for CVE-2023-23583 and CVE-2023-46835

Description of Problem

An issue has been discovered that affects Citrix Hypervisor 8.2 CU1 LTSR and may allow malicious privileged code in a guest VM to compromise an AMD-based host via a passed through PCI device (CVE-2023-46835).

In addition, Intel has disclosed a security issue affecting certain Intel CPUs (CVE-2023-23583).  Although this is not an issue in the Citrix Hypervisor product itself, we have included updated Intel microcode to mitigate this CPU hardware issue.  This issue may allow unprivileged code in a guest VM to compromise that VM and, potentially, the host.

Collectively, these issues have the following identifiers:
•    CVE-2023-23583
•    CVE-2023-46835
 

Mitigating Factors

CVE-2023-23583 only affects systems running on Intel Ice Lake or later CPUs.

CVE-2023-46835 only affects systems that have both of i) a PCI device passed through to the guest VM by the host administrator and also ii) an AMD CPU.  Customers who are not using AMD CPUs and customers who are not using the PCI passthrough feature are not affected by this issue.
 

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:

CTX583402 – https://support.citrix.com/article/CTX583402  
 

What We Are 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.
 

Subscribe to Receive Alerts

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

Reporting Security Vulnerabilities to Us

We welcome input regarding the security of our products and consider any and all potential vulnerabilities seriously. For details on our vulnerability response process and guidance on how to report security-related issues to us, 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
2023-11-15	Initial Publication