Free AI Safety Workshop — in collaboration with explainx.aiSave your seat
AgentbeamBeta
Known exploited vulnerability · VMware

CVE-2021-21985: VMware vCenter Server Improper Input Validation Vulnerability

criticalCVSS 3.1 9.8Exploited

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.

Published May 26, 2021 · Updated Aug 12, 2026

Required action

Apply updates per vendor instructions.

Advisory details

From the National Vulnerability Database. This product uses the NVD API but is not endorsed or certified by the NVD.

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.

References

How this page is made: the data panel comes from the GitHub Advisory Database, CISA’s KEV catalog, the NVD and FIRST EPSS, and updates twice a day. No analysis has been written for this entry yet. Methodology

More VMware vulnerabilities

All VMware entries