CVE-2021-21973 kev in the critical feed json
The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter Ser…
published 2021-02-24 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-9144
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Exploited
- added 2022-03-07
- epss
- 88.0%
- EPSS 88.0% chance of exploitation in 30 days, percentile 99.7%
- public exploits
- 0
- none known, plus a Nuclei check
Summary
The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue by sending a POST request to vCenter Server plugin leading to information disclosure. 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).
Patch / fix
cisa required action Apply updates per vendor instructions.
- vmware cloud_foundation 3.10.1.2, 4.2
Timeline
- Published
- Added to CISA KEV
- CISA patch deadline
- CISA SSVC: exploitation active
Known exploited
- Added
- 4 y ago
- Patch by
- 2022-03-21 (4 y ago)
- Ransomware
- Not known
- Required action
- Apply updates per vendor instructions.
- Vendor, product
- VMware, vCenter Server and Cloud Foundation
- CISA name
- VMware vCenter Server and Cloud Foundation Server Side Request Forgery (SSRF) Vulnerability
ATT&CK techniques
How it is exploited and what it leads to, in MITRE ATT&CK terms.
kev release 2025-07-28, att&ck v16.1. KEV to ATT&CK mappings by the MITRE Center for Threat-Informed Defense (Mappings Explorer, Apache-2.0). © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. Terms of use
CISA SSVC
- Exploitation
- Active, exploited in the wild
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2 y ago
Exploit prediction
88.01% chance of exploitation in the next 30 days, higher than 99.7% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Nuclei template VMware vSphere - Server-Side Request Forgery nuclei detection template
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:P/I:N/A:N |
Affected products
- n/a VMware vCenter Server
- n/a VMware Cloud Foundation
Classification
- Weakness
-
- CWE-918 Server-Side Request Forgery
- Technology feeds
References
-
vmware.com
/security/advisories/VMSA-2021-0002.html
vendor-advisory
-
cisa.gov
/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21973
government-resource, us-government-resource
Sources
- CVE List CVE-2021-21973
- NVD CVE-2021-21973
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.