VMSA-2021-0010:VMware vCenter Server updates address remote code execution and authentication vulnerabilities
23602
23 May 2021
23 May 2021
CLOSED
CRITICAL
6.5-9.8
CVE-2021-21985,CVE-2021-21986
1. Impacted Products
- VMware vCenter Server (vCenter Server)
- VMware Cloud Foundation (Cloud Foundation)
2. Introduction
Multiple vulnerabilities in the vSphere Client (HTML5) were privately reported to VMware. Updates and workarounds are available to address these vulnerabilities in affected VMware products.
3a. VMware vCenter Server updates address remote code execution vulnerability in the vSphere Client (CVE-2021-21985)
Description
The vSphere Client (HTML5) contains a remote code execution vulnerability due to lack of input validation in the Virtual SAN Health Check plug-in which is enabled by default in vCenter Server. VMware has evaluated the severity of this issue to be in the Critical severity range with a maximum CVSSv3 base score of 9.8.
Known Attack Vectors
A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server.
Resolution
To remediate CVE-2021-21985 apply the updates listed in the 'Fixed Version' column of the 'Response Matrix' below to affected deployments.
Workarounds
Workarounds for CVE-2021-21985 have been listed in the 'Workarounds' column of the 'Response Matrix' below.
Additional Documentation
None.
Notes
- The affected Virtual SAN Health Check plug-in is enabled by default in all vCenter Server deployments, whether or not vSAN is being used.
- A supplemental blog post was created for additional clarification. Please see: https://via.vmw.com/vmsa-2021-0010-blog
Acknowledgements
VMware would like to thank Ricter Z of 360 Noah Lab for reporting this issue to us.
Response Matrix:
| Product | Version | Running On | CVE Identifier | CVSSv3 | Severity | Fixed Version | Workarounds | Additional Documentation |
| vCenter Server | 7.0 | Any | CVE-2021-21985 | critical | ||||
| vCenter Server | 6.7 | Any | CVE-2021-21985 | critical | ||||
| vCenter Server | 6.5 | Any | CVE-2021-21985 | critical |
Impacted Product Suites that Deploy Response Matrix 3a Components:
3b. Authentication mechanism issue in vCenter Server Plug-ins (CVE-2021-21986)
Description
The vSphere Client (HTML5) contains a vulnerability in a vSphere authentication mechanism for the Virtual SAN Health Check, Site Recovery, vSphere Lifecycle Manager, and VMware Cloud Director Availability plug-ins. VMware has evaluated the severity of this issue to be in the Moderate severity range with a maximum CVSSv3 base score of 6.5.
Known Attack Vectors
A malicious actor with network access to port 443 on vCenter Server may perform actions allowed by the impacted plug-ins without authentication.
Resolution
To remediate CVE-2021-21986 apply the updates listed in the 'Fixed Version' column of the 'Response Matrix' below to affected deployments.
Workarounds
Workarounds for CVE-2021-21986 have been listed in the 'Workarounds' column of the 'Response Matrix' below.
Additional Documentation
None.
Notes
A supplemental blog post was created for additional clarification. Please see: https://via.vmw.com/vmsa-2021-0010-blog
Acknowledgements
None.
Response Matrix:
| Product | Version | Running On | CVE Identifier | CVSSv3 | Severity | Fixed Version | Workarounds | Additional Documentation |
| vCenter Server | 7.0 | Any | CVE-2021-21986 | moderate | ||||
| vCenter Server | 6.7 | Any | CVE-2021-21986 | moderate | ||||
| vCenter Server | 6.5 | Any | CVE-2021-21986 | moderate |
Impacted Product Suites that Deploy Response Matrix 3b Components:
4. References
Fixed Version(s) and Release Notes:
vCenter Server 7.0 U2b
Downloads and Documentation:
https://my.vmware.com/en/web/vmware/downloads/info/slug/datacenter_cloud_infrastructure/vmware_vsphere/7_0
https://docs.vmware.com/en/VMware-vSphere/7.0/rn/vsphere-vcenter-server-70u2b-release-notes.html
vCenter Server 6.7 U3n
Downloads and Documentation:
https://my.vmware.com/en/web/vmware/downloads/info/slug/datacenter_cloud_infrastructure/vmware_vsphere/6_7
https://docs.vmware.com/en/VMware-vSphere/6.7/rn/vsphere-vcenter-server-67u3n-release-notes.html
vCenter Server 6.5 U3p
Downloads and Documentation:
https://my.vmware.com/en/web/vmware/downloads/info/slug/datacenter_cloud_infrastructure/vmware_vsphere/6_5
https://docs.vmware.com/en/VMware-vSphere/6.5/rn/vsphere-vcenter-server-65u3p-release-notes.html
VMware vCloud Foundation 4.2.1
Downloads and Documentation:
https://my.vmware.com/en/web/vmware/downloads/details?downloadGroup=VCF421&productId=1121&rPId=67576
https://docs.vmware.com/en/VMware-Cloud-Foundation/4.2.1/rn/VMware-Cloud-Foundation-421-Release-Notes.html
VMware vCloud Foundation 3.10.2.1
Downloads and Documentation:
https://docs.vmware.com/en/VMware-Cloud-Foundation/3.10.2/rn/VMware-Cloud-Foundation-3102-Release-Notes.html#3.10.2.1
Mitre CVE Dictionary Links:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21985
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21986
FIRST CVSSv3 Calculator:
CVE-2021-21985: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVE-2021-21986: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
5. Change Log
2021-05-25 VMSA-2021-0010
Initial security advisory.
6. Contact
E-mail list for product security notifications and announcements:
https://lists.vmware.com/cgi-bin/mailman/listinfo/security-announce
This Security Advisory is posted to the following lists:
E-mail: [email protected]
PGP key at:
VMware Security Advisories
https://www.vmware.com/security/advisories
VMware Security Response Policy
https://www.vmware.com/support/policies/security_response.html
VMware Lifecycle Support Phases
https://www.vmware.com/support/policies/lifecycle.html
VMware Security & Compliance Blog
https://blogs.vmware.com/security
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