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FortimailApplication · Fortinet

CVE-2023-47539

CRITICAL · 9.8 CVSS v3.1 Published 2025-03-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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 access control vulnerability in FortiMail version 7.4.0 configured with RADIUS authentication and remote_wildcard enabled may allow a remote unauthenticated attacker to bypass admin login via a crafted HTTP request.

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

FortiMail 7.4.0 contains an improper access control vulnerability allowing remote unauthenticated attackers to bypass admin authentication. When configured with RADIUS authentication and remote_wildcard enabled, a crafted HTTP request can circumvent the login mechanism, granting unauthorized administrative access to the mail server.

MitigationDisable the remote_wildcard setting in FortiMail RADIUS configuration, or upgrade to a patched version once available. Verify that admin interfaces are not directly exposed to untrusted networks.

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:= 7.4.0

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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. Check FortiMail version
    Run the command: get system status or check the web interface Dashboard > Status to confirm the firmware version is 7.4.0
    Affected if Version is exactly 7.4.0 (other versions are not affected by this specific CVE)
  2. Identify RADIUS authentication configuration
    In FortiMail CLI, run: show system radius or access the web UI under System > Authentication > RADIUS Servers to see if RADIUS authentication is configured for admin access
    Affected if RADIUS authentication is configured and used for admin login (the vulnerability only applies when RADIUS is in use)
  3. Verify remote_wildcard setting status
    In FortiMail CLI, run: show system radius [server-name] and look for the setting: set remote_wildcard enable, or check via web UI under the RADIUS server configuration
    Affected if remote_wildcard is set to 'enable' (this is the specific condition that makes the vulnerability exploitable)
  4. Confirm admin interface exposure
    Review network topology and firewall policies to determine if FortiMail admin interfaces (HTTP/HTTPS ports) are reachable from untrusted networks or the internet
    Affected if Admin interface is directly exposed to untrusted networks (remote attackers would need network access to exploit this flaw)

You are affected only if FortiMail is version 7.4.0, has RADIUS authentication configured for admin access, AND has remote_wildcard enabled, with admin interface accessible to untrusted networks.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Disable the remote_wildcard setting in FortiMail RADIUS configuration, or upgrade to a patched version once available. Verify that admin interfaces are not directly exposed to untrusted networks.

Recommended fix Moderate confidence

Any FortiMail 7.4.x version beyond 7.4.0 that includes the CVE-2023-47539 patch (contact Fortinet for exact fixed release)

  1. 1. Identify current FortiMail firmware version by navigating to System > FortiGuard or checking the dashboard.
  2. 2. Contact Fortinet Technical Support or check FortiGuard (fortiguard.com) for the specific patched firmware version for CVE-2023-47539.
  3. 3. Download the patched firmware version from Fortinet support portal.
  4. 4. Review Fortinet's upgrade guide and ensure you have a backup of the configuration.
  5. 5. Upload and install the patched firmware version via System > Firmware or CLI.
  6. 6. After upgrade, verify the RADIUS authentication configuration: go to Domain & User > Authentication > RADIUS Service and confirm remote_wildcard setting.
  7. 7. Test that admin login with RADIUS authentication works correctly for legitimate users.
Caveat Review Fortinet release notes for any configuration or behavioral changes between 7.4.0 and the patched version before upgrading

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

Fix this in Fortimail Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
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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-2023-47539 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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