7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:L/Au:N/C:P/I:P/A:P
0.0004 Low
EPSS
Percentile
13.3%
Several security issues have been identified that, collectively, may allow privileged code running in a guest VM to cause the host to crash or to become unresponsive.
These issues have the following CVE identifiers:
CVE ID | Description | Vulnerability Type | Pre-conditions |
---|
CVE-2021-26930
| An attacker with the ability to execute privileged mode code in a guest can perform a denial of service attack against the host| CWE-664: Improper Control of a Resource Through its Lifetime| Administrator access in guest
CVE-2021-26931| An attacker with the ability to execute privileged mode code in a guest can perform a denial of service attack against the host| CWE-664: Improper Control of a Resource Through its Lifetime| Administrator access in guest
CVE-2021-26932| An attacker with the ability to execute privileged mode code in a guest can perform a denial of service attack against the host| CWE-664: Improper Control of a Resource Through its Lifetime| Administrator access in guest
All supported versions of Citrix Hypervisor are affected by these issues.
Citrix has released hotfixes to address these 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 LTSR: CTX294145 – <https://support.citrix.com/article/CTX294145>
Citrix Hypervisor 7.1 LTSR: CTX294143 – <https://support.citrix.com/article/CTX294143>
Citrix Hypervisor 7.0: CTX294141 – <https://support.citrix.com/article/CTX294141>
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/>.
If you require technical assistance with this issue, please contact Citrix Technical Support. Contact details for Citrix Technical Support are available at <http://www.citrix.com/site/ss/supportContacts.asp>.
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>
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.
Date | Change |
---|---|
2021-02-16 | Initial Publication |
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:L/Au:N/C:P/I:P/A:P
0.0004 Low
EPSS
Percentile
13.3%