FortiosOperating system · Fortinet
CVE-2025-53847
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 · uneditedA missing authentication for critical function vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiOS 6.4 all versions, FortiOS 6.2.9 through 6.2.17 allows attacker to execute unauthorized code or commands via specially crafted packets.
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 · moderate confidenceFortiOS contains a missing authentication vulnerability in a critical function that allows remote attackers to execute arbitrary code or commands by sending specially crafted packets without authentication. The vulnerability affects multiple version branches spanning FortiOS 6.2 through 7.6.
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
>= 6.2.9, < 7.0.18>= 7.2.0, < 7.2.12>= 7.4.0, < 7.4.9>= 7.6.0, < 7.6.4CVSS 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
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/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 checksWork through these to decide whether this CVE applies to you.
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Check FortiOS versionRun 'get system status' via CLI or check the FortiGate GUI dashboard to retrieve the firmware versionAffected if The installed version falls within any of these ranges: 6.2.9 to 7.0.17, 7.2.0 to 7.2.11, 7.4.0 to 7.4.8, or 7.6.0 to 7.6.3
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Identify exposed management interfacesRun 'get system interface' to list all network interfaces and their IP assignments, then cross-reference with 'config system global' to review management access settingsAffected if The FortiOS management interface (HTTP/HTTPS/SSH) is exposed to untrusted networks such as the internet or DMZ without restrictive access controls
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Verify administrative access policiesRun 'get firewall policy' and review 'config system admin' settings to check which source addresses are permitted to access administrative functionsAffected if Administrative access is permitted from any source (0.0.0.0/0) or from untrusted networks without IP restriction
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Check for vulnerable service statusReview output from 'diagnose system service stat' or 'diagnose sys service list' to identify listening services; the specific vulnerable function is a critical component that must be accessible for exploitationAffected if A critical network service or management function is enabled and listening on an interface accessible from untrusted networks
The environment is affected if the FortiOS version matches any of the affected version ranges AND the vulnerable function is network-accessible without authentication from an untrusted source.
Generated from the published advisory. Verify against your own configuration.
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 · scoped7.0.187.2.127.4.9
Apply the vendor-released security patches for FortiOS to address the authentication bypass. Prioritize patching for internet-facing FortiGate devices given the network-exploitable nature of this flaw.
Upgrade to FortiOS 7.0.18+, 7.2.12+, 7.4.9+, or 7.6.4+ (or latest available in each respective branch)
- 1. Identify the current FortiOS version by running 'get system status' or checking the FortiOS GUI dashboard
- 2. Based on the current version, determine the appropriate upgrade path to a fixed release
- 3. Review Fortinet's upgrade guidelines and release notes for the target version
- 4. Back up the current FortiOS configuration using 'execute backup full-config'
- 5. Plan a maintenance window as upgrades may require system restart
- 6. Download the appropriate firmware from Fortinet's support portal (fortinet.com or fortiguard.fortinet.com)
- 7. Upload the firmware via FortiOS GUI (System > Firmware) or CLI: 'execute system firmware-upgrade'
- 8. Verify the upgrade completed successfully and confirm the new version with 'get system status'
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Fortios
Scoped from the published advisory
- Consultation8.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,608.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-53847 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-53847 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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