Evidence dossier

CVE-2021-21973

CVE-2021-21973

71.3–87.0Priority evidence range

As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue by sending a POST request to vCenter Server plugin leading to information disclosure. This affects: VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).

State: PUBLISHED
Published: Feb 24, 2021
Updated: Oct 21, 2025
Evidence coverage: 85%

CISA KEVCatalog member

Apply updates per vendor instructions.

FIRST EPSS88.01%

2026-07-18 · v2026.06.15 · percentile 99.7%

Source stateNo scored conflict

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment

container

CISA ADP Vulnrichment

Jul 19, 2026Original evidence ↗

CVEderivative copy

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CVE Program Container

Jul 19, 2026Original evidence ↗

vmwareoriginal assertion

container

The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue by sending a POST request to vCenter Server plugin leading to information disclosure. This affects: VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).

Jul 19, 2026Original evidence ↗

CISA KEVoriginal assertion

observed_exploitation

VMware vCenter Server and Cloud Foundation Server Side Request Forgery (SSRF) Vulnerability

Jul 19, 2026Original evidence ↗

FIRST EPSSoriginal assertion

model_probability

Probability 0.880120000000; percentile 0.997490000000

Jul 19, 2026Original evidence ↗

Applicability

Cited product scope

Trace impact →

n/aVMware Cloud Foundation

[{"status": "affected", "version": "4.x before 4.2"}, {"status": "affected", "version": "3.x before 3.10.1.2"}]unknown

n/aVMware vCenter Server

[{"status": "affected", "version": "7.x before 7.0 U1c"}, {"status": "affected", "version": "6.7 before 6.7 U3l"}, {"status": "affected", "version": "6.5 before 6.5 U3n"}]

unknown

Unknown vendorUnknown product

cpe:2.3:a:vmware:cloud_foundation:*:*:*:*:*:*:*:*; start including 3.0; end excluding 3.10.1.2supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:cloud_foundation:*:*:*:*:*:*:*:*; start including 4.0; end excluding 4.2supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:-:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:a:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:b:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:c:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:d:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:e:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:f:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update1d:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update1e:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update1g:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update2:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update2b:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update2c:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update2d:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update2g:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update3:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update3d:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update3f:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.5:update3k:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:-:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:a:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:b:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:d:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update1:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update1b:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update2:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update2a:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update2c:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update3:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update3a:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update3b:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update3f:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update3g:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:6.7:update3j:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:7.0:-:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:7.0:a:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:7.0:b:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:7.0:c:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:7.0:d:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:7.0:update1:*:*:*:*:*:*supported

Unknown vendorUnknown product

cpe:2.3:a:vmware:vcenter_server:7.0:update1a:*:*:*:*:*:*supported

Assessments

CVSS by origin

5.3

nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

5.0

nvd@nist.govCVSS 2.0 · role PrimaryAV:N/AC:L/Au:N/C:P/I:N/A:N

5.3

134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

5.3

CISA-ADPCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Limitations and unknowns

KEV membership is authoritative for the catalog, not proof of exposure in any environment.
EPSS is a dated model probability and not an individual-environment prediction.
Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
NVD-carried upstream facts remain derivative and are not independent corroboration.
Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.