CVE-2021-21994

mediumpriority · attend · 49EPSS 0.012 · 67 %ileexploit · PoCEURUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · PoC

Likely / severe?

1.17% (67th) EPSS

CVSS 6.8 · medium

Is it mine?

12 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-26

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.

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 6.8–9.8

v2.06.8mediumAV:N/AC:M/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 6.4

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.19.3criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Psecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-287USprimaryCWE-287US

exploits (1)

Public proof-of-concept and weaponised exploit code.

mreza-en/cve-2021-21994_POCmreza-en/cve-2021-21994_POCPoC · poc_in_github

affected products (12)

Products and version ranges known to be affected.

n/a VMware ESXi and VMware Cloud Foundation≤ 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)enisa_euvdEU
Broadcom Inc. VMware Cloud Foundation3.0.0 → 3.10.2fstec_bduRU
Broadcom Inc. VMware Cloud Foundation4.0 → 4.2.1fstec_bduRU
Broadcom Inc. VMware ESXi6.5 → ESXi650-202107401-SGfstec_bduRU
Broadcom Inc. VMware ESXi6.7 → ESXi670-202103101-SGfstec_bduRU
Broadcom Inc. VMware ESXi7.0 → ESXi70U2-17630552fstec_bduRU
IBM Corp. IBM Cloud Pak System2.3.0.1 → 2.3.3.3 iFix 1fstec_bduRU
vmware cloud foundation3.0 → 3.10.2nvdUScpe:2.3:a:vmware:cloud_foundation:*:*:*:*:*:*:*:*
vmware cloud foundation4.0 → 4.3nvdUScpe:2.3:o:vmware:cloud_foundation:*:*:*:*:*:*:*:*
vmware esxi= 6.5nvdUScpe:2.3:o:vmware:esxi:*:*:*:*:*:*:*:*
vmware esxi= 6.7nvdUScpe:2.3:o:vmware:esxi:*:*:*:*:*:*:*:*
vmware esxi= 7.0nvdUScpe:2.3:o:vmware:esxi:*:*:*:*:*:*:*:*

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2021-07-13modified 2026-06-17

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+7679 more

references (8)

External citations — patches, advisories, analysis.

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