CVE-2021-21993Network attack vector

Authenticated information disclosure via unvalidated Content Library URLs

Published Sep 23, 2021 · Updated Aug 3, 2024

Server-side request forgery in VMware vCenter Server Content Library allows remote authenticated users to disclose information via POST requests. The Content Library accepts a supplied URL without adequately validating its destination, causing vCenter Server to request attacker-selected resources. The user must hold Content Library access; the documented consequence is information disclosure, with no integrity or availability impact.

CVSS severity4.3
Medium
EPSS probability0.94%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side request forgery in VMware vCenter Server Content Library allows remote authenticated users to disclose information via POST requests. The Content Library accepts a supplied URL without adequately validating its destination, causing vCenter Server to request attacker-selected resources. The user must hold Content Library access; the documented consequence is information disclosure, with no integrity or availability impact.

The record

CVE
CVE-2021-21993
Published
Sep 23, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
Unavailable
Attack vector
network
Privileges
authenticated

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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3VMwareCVSS:3.1/AV:N/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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