CVE-2020-3950Known exploitationPublic exploit

Root escalation via setuid helper hard-link abuse

Published Mar 17, 2020 · Updated Oct 21, 2025

Local privilege escalation in VMware Fusion 11.x before 11.5.3, VMRC for Mac before 11.0.1, and Horizon Client for Mac before 5.4.0 allows local users to gain root. In Fusion, a hard link to the setuid Open VMware USB Arbitrator Service helper can be launched from a user-controlled home-directory path, causing a payload there to run with effective UID 0. Normal local user access is required; VMware attributes the other affected clients to improper setuid-binary use but has not published equivalent helper-level details.

CVSS severity7.8
High
EPSS probability7.25%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Local privilege escalation in VMware Fusion 11.x before 11.5.3, VMRC for Mac before 11.0.1, and Horizon Client for Mac before 5.4.0 allows local users to gain root. In Fusion, a hard link to the setuid Open VMware USB Arbitrator Service helper can be launched from a user-controlled home-directory path, causing a payload there to run with effective UID 0. Normal local user access is required; VMware attributes the other affected clients to improper setuid-binary use but has not published equivalent helper-level details.

The record

CVE
CVE-2020-3950
Published
Mar 17, 2020
Updated
Oct 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-269, T1548.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 17, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2021Exploitation reportedCISA Known Exploited Vulnerabilities Catalog entry
  3. 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8CISACVSS:3.1/AV:L/AC:L/PR:L/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.

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No observations available

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

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1548.001Setuid and Setgid

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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