Critical

VMSA-2021-0010
6.5-9.8
2021-05-25
2021-05-25 (Initial Advisory)
CVE-2021-21985, CVE-2021-21986
VMware vCenter Server updates address remote code execution and authentication vulnerabilities (CVE-2021-21985, CVE-2021-21986)

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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
9.8
critical
FAQ
vCenter Server
6.7
Any
CVE-2021-21985
9.8
critical
FAQ
vCenter Server
6.5
Any
CVE-2021-21985
9.8
critical
FAQ

Impacted Product Suites that Deploy Response Matrix 3a Components:

Product Version Running On CVE Identifier CVSSv3 Severity Fixed Version Workarounds Additional Documentation
Cloud Foundation (vCenter Server)
4.x
Any
CVE-2021-21985
9.8
critical
FAQ
Cloud Foundation (vCenter Server)
3.x
Any
CVE-2021-21985
9.8
critical
FAQ
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
6.5
moderate
FAQ
vCenter Server
6.7
Any
CVE-2021-21986
6.5
moderate
FAQ
vCenter Server
6.5
Any
CVE-2021-21986
6.5
moderate
FAQ

Impacted Product Suites that Deploy Response Matrix 3b Components:

Product Version Running On CVE Identifier CVSSv3 Severity Fixed Version Workarounds Additional Documentation
Cloud Foundation (vCenter Server)
4.x
Any
CVE-2021-21986
6.5
moderate
FAQ
Cloud Foundation (vCenter Server)
3.x
Any
CVE-2021-21986
6.5
moderate
FAQ
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:  

security-announce@lists.vmware.com  

bugtraq@securityfocus.com  

fulldisclosure@seclists.org 

 

E-mail: security@vmware.com

PGP key at:

https://kb.vmware.com/kb/1055 

 

VMware Security Advisories

https://www.vmware.com/security/advisories 

 

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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 

 

Twitter

https://twitter.com/VMwareSRC

 

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