Description of Problem
Several issues have been discovered that affect Citrix Hypervisor 8.2 CU1 LTSR and may allow malicious privileged code in a guest VM to:
i) Compromise an AMD-based host via a passed through PCI device: CVE-2023-34326
ii) Compromise the host when a specific administrative action is taken (see Mitigating Factors below): CVE-2022-1304
iii) Cause the host to crash or become unresponsive: CVE-2023-34324
iv) Cause a different VM running on the AMD-based host to crash: CVE-2023-34327
In addition, AMD has disclosed a security issue affecting certain AMD CPUs. Although this is not an issue in the Citrix Hypervisor product itself, we have included the AMD recommended product changes to mitigate this CPU hardware issue. This issue may allow code in a guest VM to determine values from previous integer divides in code running on the same CPU core: CVE-2023-20588
Collectively, these issues have the following identifiers:
- CVE-2022-1304
- CVE-2023-20588
- CVE-2023-34324
- CVE-2023-34326
- CVE-2023-34327
Mitigating Factors
CVE-2023-34326 only affects systems that have both of a) a PCI device passed through to the guest VM by the host administrator and also b) 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.CVE-2022-1304 is only exploitable at the point that the host administrator uses the “Restore Virtual Machine Metatdata” sub-option of the “Backup, Restore and Update” menu item in the on-host xsconsole interface. Customers who do not use this sub-option are not affected by this issue.
CVE-2023-34327 only affects systems running on AMD CPUs. Customers who are not using AMD CPUs are not affected by this issue.
CVE-2023-20588 only affects systems running on AMD Zen1 CPUs. Customers who are using other generations of AMD CPUs or who are not using AMD CPUs 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:CTX575070 - https://support.citrix.com/article/CTX575070
CTX579955 - https://support.citrix.com/article/CTX579955
CTX580401 - https://support.citrix.com/article/CTX580401
CTX581053 - https://support.citrix.com/article/CTX581053
CTX581108 - https://support.citrix.com/article/CTX581108
Note that there is not a one-to-one correlation between these hotfixes and the addressed issues; we recommend that you always apply all of the 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 |
| 2023-10-10 | Initial Publication |
| 2023-10-10 | Corrected Hyperlinks |