dbcve.org
FortimailApplication · Fortinet

CVE-2023-36556

HIGH · 8.8 CVSS v3.1 Published 2023-10-10
Fix available
A fix is available. Upgrade to after 7.0.5 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
An incorrect authorization vulnerability [CWE-863] in FortiMail webmail version 7.2.0 through 7.2.2, version 7.0.0 through 7.0.5 and below 6.4.7 allows an authenticated attacker to login on other users accounts from the same web domain via crafted HTTP or HTTPs 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

FortiMail webmail contains an incorrect authorization vulnerability (CWE-863) that allows an authenticated attacker to impersonate other users within the same web domain by sending crafted HTTP/HTTPS requests. This represents horizontal privilege escalation where a user can access another user's mailboxes or session.

MitigationUpgrade FortiMail to version 7.2.3, 7.0.6, or 6.4.7 or later to obtain the vendor patch. Additionally, restrict network access to the webmail interface to trusted users to reduce attack surface.

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:>= 6.0.0, <= 6.0.12>= 6.2.0, <= 6.2.9>= 6.4.0, <= 6.4.7>= 7.0.0, <= 7.0.5= 7.2.0= 7.2.1= 7.2.2

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 FortiMail version
    Access the FortiMail administrative interface or CLI and retrieve the firmware version. In the web UI, this is typically found under System > Maintenance > Status or via the 'get system status' CLI command.
    Affected if The installed version falls within these ranges: 6.0.0-6.0.12, 6.2.0-6.2.9, 6.4.0-6.4.7, 7.0.0-7.0.5, or 7.2.0-7.2.2
  2. Confirm webmail interface is enabled
    Check the FortiMail configuration to determine if the webmail service (HTTP/HTTPS) is active. In the web UI, this is typically configured under Domain > Settings or Mail Settings > Webmail. Alternatively, use the CLI command 'show system interface' or check service bindings.
    Affected if The webmail HTTP or HTTPS service is enabled and accessible
  3. Verify network accessibility of webmail
    Determine if the webmail interface is exposed to untrusted networks. Check firewall policies, interface bindings, and access control lists that permit external or untrusted user access to FortiMail ports 80, 443, or configured webmail ports.
    Affected if The webmail interface is reachable from networks outside the trusted administrative or user pool
  4. Review webmail user session configuration
    Examine the webmail domain configuration and session management settings. In the FortiMail UI, check Domain > Settings for the relevant domain and verify session handling parameters. Look for settings that control cross-user mailbox access within the same domain.
    Affected if Webmail domains are configured and users can authenticate to access their mailboxes

You are affected if your FortiMail version is in the affected list (6.0.0-6.0.12, 6.2.0-6.2.9, 6.4.0-6.4.7, 7.0.0-7.0.5, or 7.2.0-7.2.2) AND the webmail interface is enabled and accessible to users within your environment.

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 7.0.5
Interim mitigation

Upgrade FortiMail to version 7.2.3, 7.0.6, or 6.4.7 or later to obtain the vendor patch. Additionally, restrict network access to the webmail interface to trusted users to reduce attack surface.

Recommended fix Moderate confidence

6.0.13+, 6.2.10+, 6.4.8+, 7.0.6+, or 7.2.3+ depending on current branch

  1. Identify the currently installed FortiMail version from the FortiMail web UI (System > Dashboard > Status) or CLI (get system status).
  2. Determine which version branch (6.0.x, 6.2.x, 6.4.x, 7.0.x, or 7.2.x) the current installation falls into based on the affected versions list.
  3. For FortiMail 6.0.x: Upgrade to version 6.0.13 or later.
  4. For FortiMail 6.2.x: Upgrade to version 6.2.10 or later.
  5. For FortiMail 6.4.x: Upgrade to version 6.4.8 or later.
  6. For FortiMail 7.0.x: Upgrade to version 7.0.6 or later.
  7. For FortiMail 7.2.x: Upgrade to version 7.2.3 or later.
  8. Download the appropriate firmware from the Fortinet Customer Support Portal (https://support.fortinet.com).
Caveat Review FortiMail release notes for any breaking changes between versions; firmware upgrade may require downtime and configuration backup is essential

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

Fix this in Fortimail Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,100
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,960.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-36556 — 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-2023-36556 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