Auth bypass in VMware Cloud Foundation

CVE-2021-21994

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.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.012 (66.9th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 66.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-21994: held from 0.012 to 0.012.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: +0.000

Affected products

  • VMware Cloud Foundation
  • VMware Esxi — versions 6.5, 6.7, 7.0
  • VMware Esxi And Cloud Foundation — versions VMware ESXi(7.0 before ESXi70U2-17630552, 6.7 before ESXi670-202103101-SG, 6.5 before ESXi650-202107401-SG) and VMware Cloud Foundation (4.x, 3.x before 3.10.2)

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-21994?
CVE-2021-21994 is a critical-severity vulnerability in VMware Cloud Foundation, classified under Improper Authentication. CVSS score: 9.8/10. Published 2021-07-13.
How severe is CVE-2021-21994?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-21994 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.