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                               CERT-Renater

                   Note d'Information No. 2022/VULN214

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DATE                : 24/06/2022

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running Citrix Hypervisor.

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https://support.citrix.com/article/CTX460064/citrix-hypervisor-security-update
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Citrix Hypervisor Security Update

Reference: CTX460064
Category : Medium
Created  : 23 June 2022
Modified : 23 June 2022

Description of Problem

A security issue has been identified in Citrix Hypervisor 7.1 LTSR CU2 
that may allow privileged code in a PV guest VM to compromise the host. 
Citrix believes that there would be significant complexity in performing 
this attack in Citrix Hypervisor.

This has been rated as a medium severity disclosure; the full text of 
the public bulletin can be found in Appendix A of this document.

The issue has the following CVE identifier:

   o CVE-2022-26362

In addition Intel has disclosed several issues that affect CPU hardware 
and may allow code inside a guest VM to access very small sections of 
memory data that are actively being used elsewhere on the system. 
Although this is not an issue in the Citrix Hypervisor product itself, 
Citrix is releasing hotfixes that include product changes to mitigate 
these CPU issues.

These issues have the the following CVE identifiers:

   o CVE-2022-21123
   o CVE-2022-21125
   o CVE-2022-21127
   o CVE-2022-21166

Customers who are not running PV guest VMs are not affected by the 
Citrix Hypervisor issue.
Customers who are not using Intel CPUs are not affected by the Intel CPU 
issues.


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: CTX459954- 
https://support.citrix.com/article/
CTX459954
Citrix XenServer 7.1 CU2 LTSR: CTX459953- 
https://support.citrix.com/article/
CTX459953


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
2022-06-23 Initial Publication

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+ 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 +
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