Vulmon
Description of Problem
Several issues have been identified within Citrix Hypervisor, which could, if exploited, allow:
- privileged code in a PV guest VM to read a single uninitialized 4kB page of memory (that may contain data left by a previous VM)
- privileged code in a guest VM to cause the host to crash
These vulnerabilities affect all currently supported versions of Citrix Hypervisor up to and including Citrix Hypervisor 8.1.
These issues have the following identifiers:
- CVE-2020-11740
- CVE-2020-11741
- CVE-2020-11742
- CVE-2020-11743
Note that support for PV guests was removed in Citrix Hypervisor 8.1. The provided hotfix for Citrix Hypervisor 8.1 does address both issues but customers should not assume that Citrix will address any future security issues related to PV guests running on Citrix Hypervisor 8.1.
What Customers Should Do
Hotfixes have been released to address these issues. Citrix recommends that affected customers install these hotfixes as their patching schedule allows. The hotfixes can be downloaded from the following locations:
Citrix Hypervisor 8.1: CTX270795 – https://support.citrix.com/article/CTX270795
Citrix Hypervisor 8.0: CTX270794 – https://support.citrix.com/article/CTX270794
Citrix XenServer 7.1 LTSR CU2: CTX270793 – https://support.citrix.com/article/CTX270793
Citrix XenServer 7.0: CTX270792 – https://support.citrix.com/article/CTX270792
What Citrix Is Doing
Citrix is notifying customers and channel partners about this potential security issue. This article is also available from the Citrix Knowledge Center at http://support.citrix.com/.
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.html.
Reporting Security Vulnerabilities
Citrix welcomes input regarding the security of its products and considers any and all potential vulnerabilities seriously. For guidance on how to report security-related issues to Citrix, please see the following document: CTX081743 – Reporting Security Issues to Citrix
Changelog
| Date | Change |
| 2020-04-14 | Initial Publication |