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FortiosOperating system · Fortinet

CVE-2023-42786

MEDIUM · 6.5 CVSS v3.1 Published 2025-01-14
Fix available
A fix is available. Upgrade to 7.2.6 / 7.4.2 or later.
See remediation →
71/100
Remediation priority · Elevated
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
A null pointer dereference in FortiOS versions 7.4.0 through 7.4.1, 7.2.0 through 7.2.5, 7.0 all versions, 6.4 all versions , 6.2 all versions and 6.0 all versions allows attacker to trigger a denial of service 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

A null pointer dereference vulnerability in FortiOS allows unauthenticated remote attackers to cause a denial of service by sending a crafted HTTP request to the FortiGate device. The vulnerability affects multiple version branches from 6.0 through 7.4.1 and can be triggered without authentication.

MitigationUpgrade FortiOS to a patched version (7.4.2 or later for 7.4.x, 7.2.6 or later for 7.2.x, or the latest available patched version for other affected branches). If immediate patching is not possible, consider restricting HTTP/HTTPS management access to trusted internal IP addresses via interface policies.

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
FortiosOperating system
Affected:>= 6.0.0, < 7.2.6>= 7.4.0, < 7.4.2

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 FortiOS version
    Run `get system status` or `diagnose system version` on the FortiGate CLI to retrieve the installed FortiOS version.
    Affected if The displayed version falls within the ranges >= 6.0.0 and < 7.2.6, OR >= 7.4.0 and < 7.4.2.
  2. Verify HTTP/HTTPS management is enabled
    Run `get system interface` or `show system interface` to list all interfaces and their management access settings. Look for entries showing 'http' or 'https' in the management access list.
    Affected if Any interface has HTTP or HTTPS management access enabled, making it reachable over the network.
  3. Confirm management interface is network-exposed
    Review interface policies and IP assignments. Use `show system interface <interface_name>` for each interface with management enabled to confirm the IP address and whether it is reachable from untrusted networks.
    Affected if The interface with HTTP/HTTPS management is assigned a routable IP address or is part of an untrusted zone accessible to external traffic.
  4. Check for interface-level access restrictions
    Run `show` commands for interface policies or access lists (for example, `show system interface` and review trusted host patterns) to see if management access is restricted to specific IP addresses.
    Affected if No IP-based access restrictions are configured for the management interface, meaning the HTTP service accepts requests from any source.

The device is affected if it runs a FortiOS version between 6.0.0 and 7.2.5 (inclusive) or between 7.4.0 and 7.4.1 (inclusive) AND has HTTP/HTTPS management enabled on a network-accessible interface without IP restrictions.

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 7.2.6 / 7.4.2 or later
Fixed in 7.2.67.4.2
Interim mitigation

Upgrade FortiOS to a patched version (7.4.2 or later for 7.4.x, 7.2.6 or later for 7.2.x, or the latest available patched version for other affected branches). If immediate patching is not possible, consider restricting HTTP/HTTPS management access to trusted internal IP addresses via interface policies.

Recommended fix High confidence

FortiOS 7.2.6 or later; FortiOS 7.4.2 or later (or latest stable 7.4.x release)

  1. 1. Identify current FortiOS version via 'get system status' CLI command or WebUI dashboard
  2. 2. For FortiOS 7.2.x deployments: upgrade to version 7.2.6 or later
  3. 3. For FortiOS 7.4.x deployments: upgrade to version 7.4.2 or later
  4. 4. For FortiOS 6.0.x, 6.2.x, 6.4.x, and 7.0.x deployments: plan migration path to supported fixed branch (7.2.6+ or 7.4.2+)
  5. 5. After upgrade, verify system stability and confirm fix is applied via 'get system status'
Caveat Review Fortinet release notes for compatibility notes and potential configuration changes between versions before upgrading

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

Fix this in Fortios Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2023-42786 in production — separate from our analysis above.

No notes yet

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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