CISA KEV · Known exploitedCritical

CVE-2021-21985

VMware vCenter Server

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.

CVSS: 9.8
EPSS: 100.0%
CISA KEV: Listed
Published: 2021.05.27

PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV

Exploit probability100.0%

Technical severityCVSS 9.8

Vulnerability overview

Affected product and versions

Product: VMware vCenter Server
Affected versions: VMware vCenter Server (7.x before 7.0 U2b, 6.7 before 6.7 U3n, 6.5 before 6.5 U3p) and VMware Cloud Foundation (4.x before 4.2.1, 3.x before 3.10.2.1), 6.5, 6.7, 7.0, >= 3.0 < 3.10.2.1, >= 4.0 < 4.2.1
Fixed versions: 3.10.2.1, 4.2.1

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

CISA required action

Apply updates per vendor instructions.

Due date: 2021.11.17

1
Identify
Confirm that VMware vCenter Server and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-20, CWE-470, CWE-918
KEV added: 2021.11.03
Ransomware use: 확인됨