CVE-2021-43066

Local privilege escalation via MSI path control

Published May 11, 2022 · Updated Oct 22, 2024

External path control in Fortinet FortiClient Windows 7.0.2 and earlier allows local users to escalate privileges via the MSI installer. Fortinet identifies the locus as the MSI installer but has not disclosed which pathname is attacker-controlled or how privileged installer code consumes it. A local low-privileged account is required; successful exploitation crosses into a higher-privilege context and can alter or disrupt the host.

CVSS severity7.8
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

External path control in Fortinet FortiClient Windows 7.0.2 and earlier allows local users to escalate privileges via the MSI installer. Fortinet identifies the locus as the MSI installer but has not disclosed which pathname is attacker-controlled or how privileged installer code consumes it. A local low-privileged account is required; successful exploitation crosses into a higher-privilege context and can alter or disrupt the host.

The record

CVE
CVE-2021-43066
Published
May 11, 2022
Updated
Oct 22, 2024
Vendor
Fortinet
Product
FortiClient Windows
Classifications
CWE-668, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2022CVE publishedPublication date reported by the CVE source.
  2. Oct 22, 2024Record 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=FortiClientWindows 7.0.2 7.0.1, 7.0.0, 6.4.6, 6.4.5, 6.4.4, 6.4.3, 6.4.2, 6.4.1, 6.4.0, 6.2.9, 6.2.8, 6.2.7, 6.2.6, 6.2.5, 6.2.4, 6.2.3, 6.2.2, 6.2.1, 6.2.0, 6.0.10, 6.0.9, 6.0.8, 6.0.7, 6.0.6, 6.0.5, 6.0.4, 6.0.3, 6.0.2, 6.0.1, 6.0.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Fortinet · FortiClient Windowsversion=FortiClientWindows 7.0.2 7.0.1, 7.0.0, 6.4.6, 6.4.5, 6.4.4, 6.4.3, 6.4.2, 6.4.1, 6.4.0, 6.2.9, 6.2.8, 6.2.7, 6.2.6, 6.2.5, 6.2.4, 6.2.3, 6.2.2, 6.2.1, 6.2.0, 6.0.10, 6.0.9, 6.0.8, 6.0.7, 6.0.6, 6.0.5, 6.0.4, 6.0.3, 6.0.2, 6.0.1, 6.0.0

Published CVSS scores

4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
8.4FortinetCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H
7.8NIST NVDCVSS: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.

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-668Exposure of Resource to Wrong Sphere
T1068Exploitation for Privilege Escalation

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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