dbcve.org
ForticlientApplication · Fortinet

CVE-2021-36183

HIGH · 7.8 CVSS v3.1 Published 2021-11-02
Fix available
A fix is available. Upgrade to after 7.0.1 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An improper authorization vulnerability [CWE-285] in FortiClient for Windows versions 7.0.1 and below and 6.4.2 and below may allow a local unprivileged attacker to escalate their privileges to SYSTEM via the named pipe responsible for Forticlient updates.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A local unprivileged Windows user can escalate privileges to SYSTEM by exploiting improper authorization in the named pipe responsible for FortiClient updates. The vulnerability allows a standard user to manipulate the update mechanism to execute code with elevated privileges.

MitigationUpgrade FortiClient to a version above 7.0.1 for the 7.x branch or above 6.4.2 for the 6.x branch to receive the patched software.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ForticlientApplication
Affected:>= 6.4.0, <= 6.4.2>= 7.0.0, <= 7.0.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm FortiClient is installed
    Open Windows Settings > Apps > Apps & features and search for 'FortiClient', or open Control Panel > Programs and Features and look for FortiClient in the installed programs list
    Affected if FortiClient appears in the installed programs list
  2. Find the installed FortiClient version
    Right-click on FortiClient in the Programs and Features list and select Properties, or right-click the FortiClient shortcut on the desktop and select Properties to view the version information
    Affected if The version shown falls within 6.4.0 to 6.4.2 OR 7.0.0 to 7.0.1
  3. Verify the update service exists
    Open Services (services.msc) and look for a FortiClient update-related service, or check Task Manager for running FortiClient update processes
    Affected if A FortiClient update service or process is running on the system
  4. Confirm the affected version range
    Compare your installed version number against the affected ranges: 6.4.0 through 6.4.2 or 7.0.0 through 7.0.1
    Affected if The installed version is 6.4.0, 6.4.1, 6.4.2, 7.0.0, or 7.0.1 exactly

You are affected if FortiClient is installed and the version is exactly 6.4.0, 6.4.1, 6.4.2, 7.0.0, or 7.0.1, as these versions contain the vulnerable update mechanism.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 7.0.1
Interim mitigation

Upgrade FortiClient to a version above 7.0.1 for the 7.x branch or above 6.4.2 for the 6.x branch to receive the patched software.

Recommended fix Moderate confidence

FortiClient 7.0.2+ or 6.4.3+ (whichever branch is applicable)

  1. Upgrade FortiClient for Windows to version 7.0.2 or later (for version 7.x installations)
  2. Upgrade FortiClient for Windows to version 6.4.3 or later (for version 6.4.x installations)
  3. After upgrade, verify the FortiClient version by checking Help > About FortiClient
  4. Confirm the vulnerability is remediated by ensuring the named pipe for updates has proper authorization controls
Caveat Review FortiClient release notes for your version branch to check for any feature changes or compatibility considerations before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Forticlient Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,090
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-36183 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-36183 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data