dbcve.org
FortianalyzerApplication · Fortinet

CVE-2023-42782

MEDIUM · 5.3 CVSS v3.1 Published 2023-10-10
Fix available
A fix is available. Upgrade to after 7.2.3 or later.
See remediation →
62/100
Remediation priority · Elevated
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
A insufficient verification of data authenticity vulnerability [CWE-345] in FortiAnalyzer version 7.4.0 and below 7.2.3 allows a remote unauthenticated attacker to send messages to the syslog server of FortiAnalyzer via the knoweldge of an authorized device serial number.

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 confidence

This is an authentication bypass vulnerability in FortiAnalyzer where an attacker with knowledge of a valid device serial number can send messages to the syslog server without proper authentication. The system fails to adequately verify the authenticity of data before accepting syslog messages.

MitigationUpgrade FortiAnalyzer to version 7.2.3 or above (or 7.4.1+ for the 7.4 branch) to patch the insufficient verification of data authenticity. Additionally, monitor for unauthorized syslog entries as a detective control.

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
FortianalyzerApplication
Affected:>= 6.2.0, <= 6.2.12>= 6.4.0, <= 6.4.13>= 7.0.0, <= 7.0.9>= 7.2.0, <= 7.2.3= 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
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

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. Confirm FortiAnalyzer is deployed
    Identify FortiAnalyzer installation by checking for fortianalyzer processes (ps aux | grep -i fortianalyzer) or checking network listeners for ports 514/TCP or 514/UDP which are typical syslog ports
    Affected if FortiAnalyzer software is running on the system
  2. Identify installed FortiAnalyzer version
    Run 'get system status' or 'fnsysctl get system status' from CLI, or check Web UI Dashboard > System Information widget for the Firmware version
    Affected if Version falls within ranges: 6.2.0-6.2.12, 6.4.0-6.4.13, 7.0.0-7.0.9, 7.2.0-7.2.3, or 7.4.0
  3. Verify syslog receiver is enabled
    Check syslogd configuration via CLI: 'diagnose sys syslogd list' or 'diagnose test application syslogd 1' to see if syslog receiving is active
    Affected if Syslog receiver service is enabled and listening for external syslog messages
  4. Inspect syslog destination settings
    Review syslog configuration via 'show log syslogd' or check Log Settings in Web UI to see configured syslog destinations and whether authentication is enforced
    Affected if Syslog is configured to accept unauthenticated incoming messages from network sources
  5. Review logs for suspicious syslog entries
    Examine FortiAnalyzer logs for entries with unexpected or spoofed device serial numbers using: 'execute log filter device 0' then 'execute log display' looking for anomalous source identifiers
    Affected if Logs contain syslog messages with serial numbers that do not match registered devices or show signs of injection

Environment is affected if FortiAnalyzer is running a version within the affected ranges AND syslog receiving is enabled, allowing potential unauthenticated syslog message injection.

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 7.2.3
Interim mitigation

Upgrade FortiAnalyzer to version 7.2.3 or above (or 7.4.1+ for the 7.4 branch) to patch the insufficient verification of data authenticity. Additionally, monitor for unauthorized syslog entries as a detective control.

Recommended fix Moderate confidence

Upgrade to 7.2.4 or later (7.2.x branch), or 7.0.10+/6.4.14+/6.2.13+ depending on your current branch

  1. 1. Identify the current FortiAnalyzer version by navigating to System Settings > Dashboard > System Information in the FortiAnalyzer GUI
  2. 2. Determine which version branch you are currently running (6.2.x, 6.4.x, 7.0.x, or 7.2.x)
  3. 3. For branch 7.2.x: Upgrade to version 7.2.4 or later from Fortinet's support portal
  4. 4. For branch 7.0.x: Upgrade to version 7.0.10 or later
  5. 5. For branch 6.4.x: Upgrade to version 6.4.14 or later
  6. 6. For branch 6.2.x: Upgrade to version 6.2.13 or later
  7. 7. After upgrade, verify the new version in System Information
  8. 8. Test that legitimate syslog devices can still send logs successfully
Caveat Review Fortinet release notes for your target version for any configuration or feature changes; test in staging environment before production deployment

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

Fix this in Fortianalyzer Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-42782 — 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-2023-42782 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