Summary
generated automatically from NVD dataThe vSphere Client (HTML5) in VMware vCenter Server, and also VMware Cloud Foundation, has a remote code execution flaw caused by missing input validation in the Virtual SAN Health Check plug-in, which is enabled by default. An attacker with network access to port 443 could run commands with unrestricted privileges on the operating system hosting vCenter Server. It is rated CRITICAL (CVSS v3.1 score 9.8) and is listed in the CISA KEV catalog, with known use in ransomware campaigns.
NVD 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.
⚠️ Actively exploited — CISA KEV
This CVE was added to CISA's Known Exploited Vulnerabilities catalog on 2021-11-03. It is confirmed exploited in the wild and must be patched as a priority.
Remediation deadline (US federal agencies): 2021-11-17
Used in known ransomware campaigns.
EPSS · FIRST.org
100.0%probability of exploitation in the next 30 days
Higher than 99% of scored CVEs
EPSS (Exploit Prediction Scoring System) estimates, from observed exploitation activity, how likely a CVE is to be exploited in the next 30 days. It complements CVSS, which measures severity, not likelihood. Score of 2026-10-16, recomputed daily by FIRST.org.
In-depth analysis on cveo.tech
We've published a detailed analysis of this CVE — exploitation, IOCs and mitigation.
CVSS v3.1 Score
Information
- Published
- 26 mai 2021
- Updated
- 12 août 2026
- Status
- Analyzed
- Source
- security@vmware.com
Affected products
Weaknesses (CWE)
References (7)
- http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.htmlThird Party AdvisoryVDB Entry
- http://packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Remote-Code-Execution.htmlExploitThird Party AdvisoryVDB Entry
- http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.htmlThird Party AdvisoryVDB Entry
- http://packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Remote-Code-Execution.htmlExploitThird Party AdvisoryVDB Entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21985US Government Resource
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