CVE-2021-21985
VMware vCenter Server Improper Input Validation Vulnerability
- Published
- May 26, 2021
- Updated
- Aug 12, 2026
- Assigning CNA
- vmware
- Evidence observed
- Nov 3, 2021
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HHigh · next 30 days
- Percentile
- 100.0%
- Model date
- Oct 19, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
CISA Known Exploited
This CVE appears in the CISA Known Exploited Vulnerabilities catalog.
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 port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server.
Sources
modules/exploits/linux/http/vmware_vcenter_vsan_health_rce.rb
Metasploit Framework modulesDeclared conditions
- platform: Linux,Unix($.exploit_linux/http/vmware_vcenter_vsan_health_rce.platform)
- verification: check_declared($.exploit_linux/http/vmware_vcenter_vsan_health_rce.check)
http/cves/2021/CVE-2021-21985.yaml
Nuclei TemplatesDeclared conditions
- network: http($.protocol_keys)
- verification: word($.matchers[*].type)
Responsible use
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