Vulnerability Report

CVE-2021-21985

RCE CISA KEV Active

Title: VMware vSphere Client RCE

RCE

Proof Of Concept

PoC Available for CVE-2021-21985

CWE Category CWE-20
Published Date May 26, 2021
Modified Date Oct 30, 2025
Exploit Status Available
Score 9.8 CVSS v3.1
Exploit Probability (EPSS)
100.00%

Vulnerability Summary

CVE-2021-21985: 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.

Impacted Vendors

V
vmware 2

Reference Links

http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html http://packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Remote-Code-Execution.html https://www.vmware.com/security/advisories/VMSA-2021-0010.html http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html http://packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Remote-Code-Execution.html https://www.vmware.com/security/advisories/VMSA-2021-0010.html https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21985
CVSS v3.1
Source Entity [email protected]
Severity CRITICAL
9.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v3.1
Source Entity 134c704f-9b21-4f2e-91b3-4a467353bcc0
Severity CRITICAL
9.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0
Source Entity [email protected]
Severity HIGH
10.0
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:L/Au:N/C:C/I:C/A:C

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-21985 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/Schira4396/VcenterKiller
View Code
GitHub https://github.com/W01fh4cker/VcenterKit
View Code
GitHub https://github.com/alt3kx/CVE-2021-21985_PoC
View Code
MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Stack

No specific products linked.