dbcve.org
FortimailApplication · Fortinet

CVE-2021-22129

HIGH · 8.8 CVSS v3.1 Published 2021-07-09
Fix available
A fix is available. Upgrade to 6.0.11 / 6.2.7 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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
Multiple instances of incorrect calculation of buffer size in the Webmail and Administrative interface of FortiMail before 6.4.5 may allow an authenticated attacker with regular webmail access to trigger a buffer overflow and to possibly execute unauthorized code or commands via specifically crafted HTTP requests.

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

Buffer overflow vulnerability in FortiMail's Webmail and Administrative interfaces caused by incorrect buffer size calculations, allowing authenticated attackers with regular webmail access to potentially execute arbitrary code or commands through specially crafted HTTP requests.

MitigationUpgrade FortiMail to version 6.4.5 or later to remediate this vulnerability. Prior to upgrade, schedule a maintenance window and ensure configuration backups are available.

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
FortimailApplication
Affected:<= 5.4.12>= 5.6.1, < 6.0.11>= 6.2.0, < 6.2.7>= 6.4.0, < 6.4.5

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
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/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. Identify installed FortiMail version
    Access the FortiMail CLI or web administration interface to retrieve the system version. In CLI, this is typically obtained via commands like 'get system status' or 'diagnose sys platform'. In the web interface, check Dashboard or System Settings.
    Affected if The installed version falls within any of these ranges: <=5.4.12, >=5.6.1 and <6.0.11, >=6.2.0 and <6.2.7, or >=6.4.0 and <6.4.5
  2. Confirm webmail interface is enabled
    Verify whether the FortiMail webmail interface is enabled and accessible. This can be checked in the web administration interface under Mail Settings or through CLI commands that display service configurations.
    Affected if The webmail interface is enabled and reachable over the network
  3. Determine if regular webmail users can authenticate
    Review the authentication configuration and user account settings to confirm whether standard webmail users have login capability. Check user group configurations and access policies.
    Affected if Regular webmail user authentication is permitted, allowing authenticated attackers to send specially crafted HTTP requests

Your FortiMail is affected by this CVE if it runs any version <=5.4.12, between 5.6.1-6.0.10, between 6.2.0-6.2.6, or between 6.4.0-6.4.4 AND has the webmail interface enabled with accessible user accounts.

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 6.0.11 / 6.2.7 / 6.4.5 or later
Fixed in 6.0.116.2.76.4.5
Interim mitigation

Upgrade FortiMail to version 6.4.5 or later to remediate this vulnerability. Prior to upgrade, schedule a maintenance window and ensure configuration backups are available.

Recommended fix High confidence

FortiMail 6.4.5 or later

  1. Backup FortiMail configuration and email data before initiating upgrade
  2. Schedule a maintenance window as upgrades may require downtime
  3. Download FortiMail firmware version 6.4.5 or later from Fortinet support portal
  4. Upload and install the firmware via FortiMail web UI or CLI (via 'execute upgrade')
  5. After reboot, verify the upgrade was successful and all services are running
  6. Test that the Webmail and Administrative interfaces are accessible and functioning correctly
  7. Verify the new version by running 'get system status' in CLI

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

Fix this in Fortimail Scoped from the published advisory
  • Consultation4.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,300
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,680.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-22129 — 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-2021-22129 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