CVE-2021-21994 in the critical feed json
SFCB (Small Footprint CIM Broker) as used in ESXi has an authentication bypass vulnerability.
published 2021-07-13 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-9165
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 67%
- public exploits
- 0
- none known
Summary
SFCB (Small Footprint CIM Broker) as used in ESXi has an authentication bypass vulnerability. A malicious actor with network access to port 5989 on ESXi may exploit this issue to bypass SFCB authentication by sending a specially crafted request.
Patch / fix
- vmware cloud_foundation 3.10.2, 4.3
Exploit prediction
1.17% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.8 | AV:N/AC:M/Au:N/C:P/I:P/A:P |
Affected products
- n/a VMware ESXi and VMware Cloud Foundation
Classification
- Weakness
-
- CWE-287 Improper Authentication
- Technology feeds
References
-
vmware.com
/security/advisories/VMSA-2021-0014.html
vendor-advisory
Sources
- CVE List CVE-2021-21994
- NVD CVE-2021-21994
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.