---
id: CVE-2021-21985
title: >-
  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
summary: >-
  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
  por…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-918
  - CWE-20
  - CWE-470
  - CWE-918
vendor: vmware
product: vcenter_server
affected:
  - vcenter_server = 6.5
  - vcenter_server = 6.7
  - vcenter_server = 7.0
  - 'cloud_foundation >= 3.0, < 3.10.2.1'
  - 'cloud_foundation >= 4.0, < 4.2.1'
patched:
  - cloud_foundation 4.2.1
published: '2021-05-26'
updated: '2026-08-12'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-21985'
references:
  - url: >-
      http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html
    label: security@vmware.com
  - url: >-
      http://packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Remote-Code-Execution.html
    label: security@vmware.com
  - url: 'https://www.vmware.com/security/advisories/VMSA-2021-0010.html'
    label: security@vmware.com
  - url: >-
      http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      http://packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Remote-Code-Execution.html
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.vmware.com/security/advisories/VMSA-2021-0010.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21985
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - kev
  - in-the-wild
  - exploit-available
epss: 0.99999
epssPercentile: 0.99993
kev: true
kevDateAdded: '2021-11-03'
kevDueDate: '2021-11-17'
kevRansomware: true
exploited: true
ingestedAt: '2026-08-12T19:54:26.018Z'
exploits:
  github: 10
  githubRepos:
    - 'https://github.com/bigbroke/CVE-2021-21985'
    - 'https://github.com/alt3kx/CVE-2021-21985_PoC'
    - 'https://github.com/onSec-fr/CVE-2021-21985-Checker'
  metasploit:
    - exploit/linux/http/vmware_vcenter_vsan_health_rce
  nuclei:
    - CVE-2021-21985
  checkedAt: '2026-09-19T16:22:51.215Z'
exploitAvailable: true
---

## Overview

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.

## Affected

- `vcenter_server = 6.5`
- `vcenter_server = 6.7`
- `vcenter_server = 7.0`
- `cloud_foundation >= 3.0, < 3.10.2.1`
- `cloud_foundation >= 4.0, < 4.2.1`

## Remediation

Upgrade past the affected range:

- `cloud_foundation 4.2.1`