CVE-2021-22016Network attack vector

Malicious script execution via reflected XSS

Published Sep 23, 2021 · Updated Aug 3, 2024

Reflected cross-site scripting in VMware vCenter Server 6.7 before 6.7 U3o and Cloud Foundation 3.x before 3.10.2.2 allows attackers to execute malicious scripts through a crafted link. The affected web interface reflects unsanitized request input into generated pages, allowing script content to run in a victim's browser when the victim clicks the link. Exploitation requires social engineering and victim interaction; the documented impact is script execution in the browser context, with no reported direct service interruption.

CVSS severity4.0
Medium
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected cross-site scripting in VMware vCenter Server 6.7 before 6.7 U3o and Cloud Foundation 3.x before 3.10.2.2 allows attackers to execute malicious scripts through a crafted link. The affected web interface reflects unsanitized request input into generated pages, allowing script content to run in a victim's browser when the victim clicks the link. Exploitation requires social engineering and victim interaction; the documented impact is script execution in the browser context, with no reported direct service interruption.

The record

CVE
CVE-2021-22016
Published
Sep 23, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.0Rapid7AV:N/AC:M/Au:N/C:N/I:P/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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

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.

Technologies

Your stack

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Your stack

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