{"id":"CVE-2021-21985","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-21985","generatedAt":"2026-10-27T23:27:26.052Z","title":"VMware vCenter Server Improper Input Validation Vulnerability","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.","published":"2021-05-26T15:15:08.000Z","lastModified":"2026-08-12T05:17:37.000Z","status":"Analyzed","sourceIdentifier":"security@vmware.com","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-918","CWE-20","CWE-470"],"affected":["vmware/vcenter server","vmware/cloud foundation"],"epss":{"score":0.99999,"percentile":0.99993,"date":"2026-10-26","history":[]},"kev":{"listed":true,"dateAdded":"2021-11-03","dueDate":"2021-11-17","knownRansomwareCampaignUse":"Known","notes":"Apply updates per vendor instructions.\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-21985"},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"Known to be exploited in the wild (CISA KEV, CISA remediation deadline 17 November 2021). Treat as an emergency change: patch or isolate now, then hunt for prior compromise."},"changes":[],"references":[{"url":"http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html","tags":["Third Party Advisory","VDB Entry"],"source":"security@vmware.com"},{"url":"http://packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Remote-Code-Execution.html","tags":["Exploit","Third Party Advisory","VDB Entry"],"source":"security@vmware.com"},{"url":"https://www.vmware.com/security/advisories/VMSA-2021-0010.html","tags":["Vendor Advisory"],"source":"security@vmware.com"},{"url":"http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Remote-Code-Execution.html","tags":["Exploit","Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.vmware.com/security/advisories/VMSA-2021-0010.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21985","tags":["US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-21985","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}