CVE-2021-21972: VMware vCenter Server Remote Code Execution Vulnerability
Reference page built from the source records below, each shown as its source publishes it. Dataset version ref-ace930806667, updated 2026-11-02T23:39:54.475Z.
CISA Known Exploited Vulnerabilities
- Name
- VMware vCenter Server Remote Code Execution Vulnerability
- Vendor
- VMware
- Product
- vCenter Server
- Added to the catalog
- 2021-11-03
- Due date for US federal agencies
- 2021-11-17
- Weaknesses
- CWE-23
- Catalog version
- 2026.10.30
VMware vCenter Server vSphere Client contains a remote code execution vulnerability in a vCenter Server plugin which allows an attacker with network access to port 443 to execute commands with unrestricted privileges on the underlying operating system.
Required action (CISA)
Apply updates per vendor instructions.
Ransomware use: CISA marks this vulnerability as known to be used in ransomware campaigns. CISA does not say which group used it.
Links in CISA's notes
Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json
NVD analysis
- Status
- Analyzed
- Published
- 2021-02-24T17:15:15.833
- Last modified
- 2026-08-12T05:17:35.260
- Weaknesses
- CWE-22
The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin. 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. This affects VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).
| Metric | Score | Severity | Vector | Scored by |
|---|---|---|---|---|
| CVSS 3.1 | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | [email protected] (Primary) |
| CVSS 3.1 | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
| CVSS 2.0 | 10 | HIGH | AV:N/AC:L/Au:N/C:C/I:C/A:C | [email protected] (Primary) |
References
- http://packetstormsecurity.com/files/161590/VMware-vCenter-Server-7.0-Arbitrary-File-Upload.html (Exploit, Third Party Advisory, VDB Entry)
- http://packetstormsecurity.com/files/161695/VMware-vCenter-Server-File-Upload-Remote-Code-Execution.html (Exploit, Third Party Advisory, VDB Entry)
- http://packetstormsecurity.com/files/163268/VMware-vCenter-6.5-6.7-7.0-Remote-Code-Execution.html (Exploit, Third Party Advisory, VDB Entry)
- https://www.vmware.com/security/advisories/VMSA-2021-0002.html (Vendor Advisory)
- http://packetstormsecurity.com/files/161590/VMware-vCenter-Server-7.0-Arbitrary-File-Upload.html (Exploit, Third Party Advisory, VDB Entry)
- http://packetstormsecurity.com/files/161695/VMware-vCenter-Server-File-Upload-Remote-Code-Execution.html (Exploit, Third Party Advisory, VDB Entry)
- http://packetstormsecurity.com/files/163268/VMware-vCenter-6.5-6.7-7.0-Remote-Code-Execution.html (Exploit, Third Party Advisory, VDB Entry)
- https://www.vmware.com/security/advisories/VMSA-2021-0002.html (Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21972 (US Government Resource)
This product uses the NVD API but is not endorsed or certified by the NVD.
Read on 2026-11-02T23:41:51.476Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2021-21972
CVE record
- Assigner
- vmware
- State
- PUBLISHED
- Published
- 2021-02-24T16:42:05.000Z
- Updated
- 2026-08-12T03:55:37.234Z
- Problem types
- Remote code execution vulnerability
The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin. 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. This affects VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).
References
- https://www.vmware.com/security/advisories/VMSA-2021-0002.html
- http://packetstormsecurity.com/files/161590/VMware-vCenter-Server-7.0-Arbitrary-File-Upload.html
- http://packetstormsecurity.com/files/161695/VMware-vCenter-Server-File-Upload-Remote-Code-Execution.html
- http://packetstormsecurity.com/files/163268/VMware-vCenter-6.5-6.7-7.0-Remote-Code-Execution.html
Read on 2026-11-03T01:06:05.405Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2021/21xxx/CVE-2021-21972.json
Detection rules (SigmaHQ)
SigmaHQ rules whose own tags name this CVE. Each rule page shows the rule as its author published it.
- CVE-2021-21972 VSphere Exploitation (status test, level high)
Defensive techniques (MITRE D3FEND)
D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.
CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- Isolate: Application-based Process Isolation (acts on Subroutine)
- Model: Software Inventory (acts on Software)
- Harden: Variable Initialization (acts on Subroutine)
- Harden: Software Update (acts on Software)
- Harden: Domain Logic Validation (acts on Subroutine)
- Restore: Restore Software (acts on Software)
- Model: Asset Vulnerability Enumeration (acts on Software)
- Harden: Trusted Library (acts on Subroutine)
- Harden: Credential Scrubbing (acts on Subroutine)
D3FEND ontology version 1.6.0.
Read on 2026-11-02T23:53:56.145Z under licence d3fend-terms-of-use@f98cbc7e from https://d3fend.mitre.org/api/weakness/cwe/CWE-22.json
MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
"The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/
Sources and licences
CISA
Source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30, CC0 1.0. Use of this data does not imply endorsement by CISA or DHS.
National Vulnerability Database (NIST)
This product uses the NVD API but is not endorsed or certified by the NVD.
NVD API Terms of Use (NIST publications in the public domain, 17 U.S.C. 105)
CVE Program, The MITRE Corporation
Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation. CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.
SigmaHQ
"CVE-2021-21972 VSphere Exploitation" by Bhabesh Raj (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-21972/web_cve_2021_21972_vsphere_unauth_rce_exploit.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseMITRE D3FEND
MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
"The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/MITRE D3FEND Terms of Use (site + knowledge graph); source repo MIT
Cite this page
Dragons Eye Ransomware Tracker, "CVE-2021-21972: VMware vCenter Server Remote Code Execution Vulnerability",
entity page, dataset version ref-ace930806667, updated 2026-11-02T23:39:54.475Z,
https://ransomware-tracker.com/cve/CVE-2021-21972 (accessed 2026-11-03).
Underlying source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30.
Underlying source: National Vulnerability Database (NIST), CVE API 2.0, record last modified 2026-08-12T05:17:35.260.
Underlying source: CVE List (CVE Program, The MITRE Corporation), record updated 2026-08-12T03:55:37.234Z.
Underlying source: SigmaHQ rule 179ed852-0f9b-4009-93a7-68475910fd86, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: MITRE D3FEND, ontology version 1.6.0.
Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.