=====================================================================

                                  CERT-Renater

                        Note d'Information No. 2023/VULN475

_____________________________________________________________________

DATE                : 16/11/2023

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running Citrix Hypervisor, XenServer.

=====================================================================
https://support.citrix.com/article/CTX583037/citrix-hypervisor-security-bulletin-for-cve202323583-and-cve202346835
_____________________________________________________________________

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

Reference: CTX583037
Category : Severity: High
Created  : 15 November 2023
Modified : 15 November 2023

Applicable Products

   o Citrix Hypervisor
   o XenServer


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:
o CVE-2023-23583
o 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



=========================================================
+ CERT-RENATER        |    tel : 01-53-94-20-44         +
+ 23/25 Rue Daviel    |    fax : 01-53-94-20-41         +
+ 75013 Paris         |   email:cert@support.renater.fr +
=========================================================