CVE-2021-21972Known exploitationPublic exploitNetwork attack vector

Unauthenticated command execution via traversable OVA extraction

Published Feb 24, 2021 · Updated Aug 12, 2026

Path traversal in VMware vCenter Server 6.5, 6.7, and 7.x allows remote attackers to execute commands through port 443. The unauthenticated uploadOvaFile handler extracts attacker-supplied OVA tar entries beneath /tmp/unicorn_ova_dir without rejecting parent-directory paths, allowing files to be written outside that directory. The vROps plugin endpoint is present in default installations, and Cloud Foundation 3.x and 4.x are affected through their embedded vCenter Server component.

CVSS severity9.8
Critical
EPSS probability99.87%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in VMware vCenter Server 6.5, 6.7, and 7.x allows remote attackers to execute commands through port 443. The unauthenticated uploadOvaFile handler extracts attacker-supplied OVA tar entries beneath /tmp/unicorn_ova_dir without rejecting parent-directory paths, allowing files to be written outside that directory. The vROps plugin endpoint is present in default installations, and Cloud Foundation 3.x and 4.x are affected through their embedded vCenter Server component.

The record

CVE
CVE-2021-21972
Published
Feb 24, 2021
Updated
Aug 12, 2026
Vendor
VMware
Product
VMware vCenter Server
Classifications
CWE-23, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2021Exploitation reportedCISA Known Exploited Vulnerabilities listing
  3. Aug 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 IPsShadowserver observations through Sep 16, 2026. Gaps indicate unavailable data.
Sep 10, 2026Sep 16, 2026
View daily counts
Reporting dayUnique IPs
Sep 10, 20261
Sep 11, 2026Unavailable
Sep 12, 2026Unavailable
Sep 13, 2026Unavailable
Sep 14, 2026Unavailable
Sep 15, 2026Unavailable
Sep 16, 2026Unavailable
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-23Relative Path Traversal
T1190Exploit Public-Facing Application

Public exploit references

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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