id: CVE-2021-21985 info: name: VMware vSphere Client (HTML5) - Remote Code Execution author: D0rkerDevil severity: critical 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. remediation: | Apply the necessary security patches or updates provided by VMware to mitigate this vulnerability. reference: - https://www.vmware.com/security/advisories/VMSA-2021-0010.html - https://github.com/alt3kx/CVE-2021-21985_PoC - https://nvd.nist.gov/vuln/detail/CVE-2021-21985 - http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html classification: cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H cvss-score: 9.8 cve-id: CVE-2021-21985 cwe-id: CWE-20 epss-score: 0.9737 epss-percentile: 0.99873 cpe: cpe:2.3:a:vmware:vcenter_server:6.5:-:*:*:*:*:*:* metadata: max-request: 1 vendor: vmware product: vcenter_server tags: packetstorm,cve,cve2021,rce,vsphere,vmware,kev http: - raw: - | POST /ui/h5-vsan/rest/proxy/service/com.vmware.vsan.client.services.capability.VsanCapabilityProvider/getClusterCapabilityData HTTP/1.1 Host: {{Hostname}} Accept: */* Content-Type: application/json {"methodInput":[{"type":"ClusterComputeResource","value": null,"serverGuid": null}]} matchers: - type: word part: body words: - '{"result":{"isDisconnected":' # digest: 4a0a0047304502200f0ac689c7c819ceb54425c0ba5388b355cc885c3b12fc7ed423ceb1f887551a022100d99be29974ecbac1c324f5035cc11a4759ca981f846aca6e0fd2230e6f2cb8d9:922c64590222798bb761d5b6d8e72950