kbrain

CVE-2021-21994

CRITICAL · CVSS 9.8EPSS 1.2%EU EUVD

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.

Key facts

CVSS score
9.8 (v3.1)
Severity
CRITICAL
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-287
EPSS score
1.2% (67th percentile)
In CISA KEV
No
In EU EUVD
Yes (EUVD-2021-9165)
Published
July 13, 2021
NVD last modified
June 17, 2026
Status
Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-9165 in the EU Vulnerability Database. Last updated in EUVD on August 3, 2024.

View on the EU Vulnerability Database

Affected products

  • vmware / cloud foundation
  • vmware / cloud foundation
  • vmware / esxi
  • vmware / esxi
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  • vmware / esxi
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  • vmware / esxi
  • vmware / esxi
  • vmware / esxi

and 188 more…

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

References

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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