CVE-2021-21994

9.8 CRITICAL
Published: July 13, 2021 Modified: October 31, 2025

Description

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://www.vmware.com/security/advisories/VMSA-2021-0014.html
Source: security@vmware.com
Vendor Advisory
https://www.vmware.com/security/advisories/VMSA-2021-0014.html
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.8 / 10.0
EPSS (Exploit Probability)
0.2%
47th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

vmware