FortiwebApplication · Fortinet
CVE-2023-23783
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 use of externally-controlled format string in Fortinet FortiWeb version 7.0.0 through 7.0.1, FortiWeb 6.4 all versions allows attacker to execute unauthorized code or commands via specially crafted command arguments.
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 confidenceThis is a format string vulnerability in FortiWeb where user-supplied input from command arguments is passed directly to a format string function without proper sanitization. Attackers can inject format specifiers (e.g., %x, %n) to read stack memory or write arbitrary data, potentially achieving remote code execution.
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
FortiwebApplication
>= 6.4.0, < 6.4.2>= 7.0.0, < 7.0.2CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/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 checksWork through these to decide whether this CVE applies to you.
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Check FortiWeb versionRun the command 'get system status' or 'fwb -v' via CLI to retrieve the installed FortiWeb versionAffected if The installed version falls within 6.4.0 to 6.4.1, or 7.0.0 to 7.0.1 (inclusive of the lower bounds, exclusive of 6.4.2 and 7.0.2)
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Verify administrative access configurationCheck the administrative interface settings via 'show system admin' or review the web UI under System > Administration > AdministratorsAffected if Remote administrative access is enabled and exposed to untrusted networks (the vulnerability involves command arguments that could be supplied by an authenticated administrator)
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Inspect CLI command loggingReview FortiWeb CLI logs or audit logs for any entries containing format string specifiers like %x, %n, %s in command argumentsAffected if Logs show format string characters in executed commands, indicating potential exploitation attempts or vulnerable code paths
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Check for unauthorized command executionExamine administrative audit logs for unexpected or anomalous CLI commands, particularly those involving system operationsAffected if Commands were executed that were not initiated by legitimate administrators or contain unusual format string patterns
A FortiWeb instance is affected if it runs version 6.4.0-6.4.1 or 7.0.0-7.0.1 and has an attacker capable of supplying malicious format string characters through command arguments to the system.
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 · scoped6.4.27.0.2
Update FortiWeb to the latest version (beyond 7.0.1 and 6.4.x) to obtain the vendor patch. If immediate patching is not possible, restrict access to administrative interfaces and implement input validation on all command arguments.
FortiWeb 7.0.2 or later (or 6.4.2 for 6.4.x branch)
- 1. Check current FortiWeb version by navigating to System > Firmware or using CLI command 'get system status'
- 2. Download the fixed firmware version (7.0.2 or later for 7.0.x branch, or 6.4.2 or later for 6.4.x branch) from Fortinet Customer Support portal
- 3. Backup current FortiWeb configuration before upgrading
- 4. Upload and install the fixed firmware via Web UI (System > Firmware) or CLI (execute system firmware-upgrade)
- 5. After upgrade, verify the version and confirm the vulnerability is resolved
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Fortiweb
Scoped from the published advisory
- Consultation4.0 h
- Implementation12.0 h
- Testing8.0 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 $7,808.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-23783 — 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-2023-23783 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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- 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
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