CVE-2021-21973Known exploitationNetwork attack vector

Information disclosure via unvalidated plugin URLs

Published Feb 24, 2021 · Updated Oct 21, 2025

SSRF in VMware vCenter Server and Cloud Foundation allows remote attackers to disclose information through port 443 POST requests. The HTML5 vSphere Client's default vROps plugin accepts a supplied URL without adequate destination validation and makes the server-side request. Network access to the management HTTPS service is sufficient; the reported consequence is information disclosure, not data modification or service interruption.

CVSS severity5.3
Medium
EPSS probability87.64%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in VMware vCenter Server and Cloud Foundation allows remote attackers to disclose information through port 443 POST requests. The HTML5 vSphere Client's default vROps plugin accepts a supplied URL without adequate destination validation and makes the server-side request. Network access to the management HTTPS service is sufficient; the reported consequence is information disclosure, not data modification or service interruption.

The record

CVE
CVE-2021-21973
Published
Feb 24, 2021
Updated
Oct 21, 2025
Vendor
VMware
Product
VMware vCenter Server
Classifications
CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.5 before 6.5 U3n
  2. Affected versionversion=6.7 before 6.7 U3l
  3. Affected versionversion=7.x before 7.0 U1c

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

VMware · VMware vCenter Serverversion=6.5 before 6.5 U3n; version=6.7 before 6.7 U3l; version=7.x before 7.0 U1c
VMware · VMware Cloud Foundationversion=3.x before 3.10.1.2; version=4.x before 4.2

Published CVSS scores

5.3VMwareCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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