CVE-2021-21985
Summary
| CVE | CVE-2021-21985 |
|---|---|
| State | PUBLISHED |
| Assigner | vmware |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2021-05-26 15:15:07 UTC |
| Updated | 2026-08-12 05:17:36 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.999990000 probability, percentile 0.999920000 (date 2026-08-21)
CISA KEV: Listed on 2021-11-03; due 2021-11-17; ransomware use Known
Problem Types: CWE-918 | CWE-20 | CWE-470 | Remote code execution vulnerability | CWE-20 CWE-20 Improper Input Validation | CWE-470 CWE-470 Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') | CWE-918 CWE-918 Server-Side Request Forgery (SSRF)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | ADP | DECLARED | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 2.0 | [email protected] | Primary | 10 | AV:N/AC:L/Au:N/C:C/I:C/A:C |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0 Breakdown
Access Vector
NetworkAccess Complexity
LowAuthentication
NoneConfidentiality
CompleteIntegrity
CompleteAvailability
CompleteAV:N/AC:L/Au:N/C:C/I:C/A:C
CISA Known Exploited Vulnerability
| Vendor | VMware |
|---|---|
| Product | vCenter Server |
| Name | VMware vCenter Server Improper Input Validation Vulnerability |
| Required Action | Apply updates per vendor instructions. |
| Notes | https://nvd.nist.gov/vuln/detail/CVE-2021-21985 |
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Vmware | Cloud Foundation | All | All | All | All |
| Application | Vmware | Vcenter Server | 6.5 | - | All | All |
| Application | Vmware | Vcenter Server | 6.5 | a | All | All |
| Application | Vmware | Vcenter Server | 6.5 | b | All | All |
| Application | Vmware | Vcenter Server | 6.5 | c | All | All |
| Application | Vmware | Vcenter Server | 6.5 | d | All | All |
| Application | Vmware | Vcenter Server | 6.5 | e | All | All |
| Application | Vmware | Vcenter Server | 6.5 | f | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update1 | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update1b | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update1c | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update1d | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update1e | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update1g | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update2 | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update2b | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update2c | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update2d | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update2g | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update3 | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update3d | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update3f | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update3k | All | All |
| Application | Vmware | Vcenter Server | 6.5 | update3n | All | All |
| Application | Vmware | Vcenter Server | 6.7 | - | All | All |
| Application | Vmware | Vcenter Server | 6.7 | a | All | All |
| Application | Vmware | Vcenter Server | 6.7 | b | All | All |
| Application | Vmware | Vcenter Server | 6.7 | d | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update1 | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update1b | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update2 | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update2a | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update2c | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update3 | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update3a | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update3b | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update3f | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update3g | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update3j | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update3l | All | All |
| Application | Vmware | Vcenter Server | 6.7 | update3m | All | All |
| Application | Vmware | Vcenter Server | 7.0 | - | All | All |
| Application | Vmware | Vcenter Server | 7.0 | a | All | All |
| Application | Vmware | Vcenter Server | 7.0 | b | All | All |
| Application | Vmware | Vcenter Server | 7.0 | c | All | All |
| Application | Vmware | Vcenter Server | 7.0 | d | All | All |
| Application | Vmware | Vcenter Server | 7.0 | update1 | All | All |
| Application | Vmware | Vcenter Server | 7.0 | update1a | All | All |
| Application | Vmware | Vcenter Server | 7.0 | update1c | All | All |
| Application | Vmware | Vcenter Server | 7.0 | update1d | All | All |
| Application | Vmware | Vcenter Server | 7.0 | update2 | All | All |
| Application | Vmware | Vcenter Server | 7.0 | update2a | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Na | VMware VCenter Server And VMware Cloud Foundation | affected VMware vCenter Server (7.x before 7.0 U2b, 6.7 before 6.7 U3n, 6.5 before 6.5 U3p) and VMware Cloud Foundation (4.x before 4.2.1, 3.x before 3.10.2.1) | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| VMware vCenter Server Virtual SAN Health Check Remote Code Execution ≈ Packet Storm | af854a3a-2127-422b-91ae-364da2661108 | packetstormsecurity.com | Exploit, Third Party Advisory, VDB Entry |
| www.cisa.gov/known-exploited-vulnerabilities-catalog | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.cisa.gov | US Government Resource |
| Access Denied | af854a3a-2127-422b-91ae-364da2661108 | www.vmware.com | Vendor Advisory |
| VMware Security Advisory 2021-0010 ≈ Packet Storm | af854a3a-2127-422b-91ae-364da2661108 | packetstormsecurity.com | Third Party Advisory, VDB Entry |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
| CISA Known Exploited Vulnerabilities catalog | CISA | www.cisa.gov | kev |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2021-11-03T00:00:00.000Z | CVE-2021-21985 added to CISA KEV |
Legacy QID Mappings
- 216259 VMware vCenter Server 7.0 Update 7.0 U2b Missing (VMSA-2021-0010)
- 216260 VMware vCenter Server 6.7 Update 6.7 U3n Missing (VMSA-2021-0010)
- 216261 VMware vCenter Server 6.5 Update 6.5 U3p Missing (VMSA-2021-0010)
- 730102 VMware vCenter Server Remote Code Execution (RCE) Vulnerability (VMSA-2021-0010) (UNAUTHENTICATED))