CVE-2021-21985

9.8 CRITICAL CISA KEV - Actively Exploited
Published: May 26, 2021 Modified: October 30, 2025

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. 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.

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

Login to generate AI explanation

CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html
Source: security@vmware.com
Third Party Advisory VDB Entry
https://www.vmware.com/security/advisories/VMSA-2021-0010.html
Source: security@vmware.com
Vendor Advisory
http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Remote-Code-Execution.html
Source: af854a3a-2127-422b-91ae-364da2661108
Exploit Third Party Advisory VDB Entry
https://www.vmware.com/security/advisories/VMSA-2021-0010.html
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21985
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
US Government Resource

7 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.8 / 10.0
EPSS (Exploit Probability)
94.4%
100th percentile
Exploitation Status
Actively Exploited
Remediation due: 2021-11-17

Affected Vendors

vmware