dbcve.org
FortiwebApplication · Fortinet

CVE-2023-23781

HIGH · 8.8 CVSS v3.1 Published 2023-02-16
Fix available
A fix is available. Upgrade to 6.3.20 / 7.0.2 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
A stack-based buffer overflow vulnerability [CWE-121] in FortiWeb version 7.0.1 and below, 6.4 all versions, version 6.3.19 and below SAML server configuration may allow an authenticated attacker to achieve arbitrary code execution via specifically crafted XML files.

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 stack-based buffer overflow (CWE-121) in FortiWeb's SAML server configuration parser when processing specifically crafted XML files allows authenticated attackers to overwrite return addresses on the stack and achieve arbitrary code execution.

MitigationUpgrade FortiWeb to version 7.0.2 or higher, 6.4.2 or higher, or 6.3.20 or higher. Until patched, limit access to the SAML configuration interface to trusted administrators only.

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
Affected:>= 6.3.0, < 6.3.20>= 6.4.0, <= 6.4.2>= 7.0.0, < 7.0.2

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 FortiWeb version
    Log into the FortiWeb CLI and run 'get system status' or check the GUI dashboard to view the firmware version.
    Affected if The installed version falls within 6.3.0 to <6.3.20, 6.4.0 to 6.4.2, or 7.0.0 to <7.0.2.
  2. Confirm SAML server feature is configured
    In FortiWeb GUI, navigate to Server Infrastructure > SAML or use CLI 'show saml' to check if any SAML server configurations exist.
    Affected if SAML server configurations are defined on the device.
  3. Verify SAML configuration interface access
    Review administrative access settings via System > Administration > Administrators in GUI or 'show system admin' in CLI to see which users have access to SAML configuration.
    Affected if Untrusted or unauthorized users have administrative access to modify SAML settings.
  4. Check for recent SAML configuration changes
    Review FortiWeb logs and audit trails for recent modifications to SAML server configurations, particularly XML file imports.
    Affected if SAML XML configuration files were recently imported or modified.

You are affected if FortiWeb runs a version in the affected range AND SAML server is configured, allowing authenticated users to trigger the XML parser overflow.

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 6.3.20 / 7.0.2 or later
Fixed in 6.3.207.0.2
Interim mitigation

Upgrade FortiWeb to version 7.0.2 or higher, 6.4.2 or higher, or 6.3.20 or higher. Until patched, limit access to the SAML configuration interface to trusted administrators only.

Recommended fix High confidence

FortiWeb 6.3.20, 6.4.3, or 7.0.2 (depending on your current major version branch)

  1. 1. Back up the current FortiWeb configuration via the web UI (System > Maintenance > Backup & Restore) or CLI 'execute backup full-config'
  2. 2. Identify your current FortiWeb version from the web UI (Dashboard > Status widget) or CLI 'get system status'
  3. 3. Download the appropriate fixed version from the Fortinet Support Portal: FortiWeb 6.3.20, 6.4.3, or 7.0.2 (choose the version that corresponds to your current major.minor branch)
  4. 4. Upload the firmware file via the web UI (System > Maintenance > Firmware) or CLI 'execute firmware upgrade'
  5. 5. Reboot the device when prompted and wait for the system to come back online
  6. 6. Verify the upgrade was successful by checking the version in the Dashboard or CLI 'get system status'
  7. 7. Verify SAML server configuration functionality is working correctly
Caveat Review FortiWeb release notes for your target version to check for any configuration or feature changes between your current version and the upgrade version

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

Fix this in Fortiweb 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
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-23781 — 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-2023-23781 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