FortiosOperating system · Fortinet
CVE-2018-13380
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 Cross-site Scripting (XSS) vulnerability in Fortinet FortiOS 6.0.0 to 6.0.4, 5.6.0 to 5.6.7, 5.4.0 to 5.4.12, 5.2 and below and Fortinet FortiProxy 2.0.0, 1.2.8 and below under SSL VPN web portal allows attacker to execute unauthorized malicious script code via the error or message handling parameters.
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 confidenceA stored Cross-site Scripting (XSS) vulnerability exists in the SSL VPN web portal of Fortinet FortiOS (versions 5.2 through 6.0.4) and FortiProxy (versions 1.2.8 and below, 2.0.0). The vulnerability resides in error or message handling parameters where unsanitized user input is reflected back to the browser, allowing attackers to execute arbitrary JavaScript code in the context of authenticated VPN users.
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
<= 5.2>= 5.4.0, <= 5.4.12>= 5.6.0, <= 5.6.7>= 6.0.0, <= 6.0.4
FortiproxyApplication
<= 1.2.8= 2.0.0CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify FortiOS versionRun 'get system status' or 'fwconsole -i version' via CLI to retrieve the installed FortiOS versionAffected if version falls within 5.2 to 5.4.12, 5.6.0 to 5.6.7, or 6.0.0 to 6.0.4
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Identify FortiProxy versionRun 'get system status' via CLI to retrieve the installed FortiProxy versionAffected if version is 1.2.8 or below, or exactly 2.0.0
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Confirm SSL VPN web portal is enabledNavigate to VPN > SSL-VPN Settings in the web UI or run 'get vpn ssl settings' via CLI to verify the portal is activeAffected if SSL VPN web portal access is enabled and users can authenticate to the portal
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Inspect error and message handling parametersLog into the SSL VPN web portal as an authenticated user, submit crafted input in error message fields or message parameters (such as username, custom messages, or error display fields), then refresh the page to see if the input is reflected without sanitizationAffected if unsanitized user-supplied input is reflected back and executed as JavaScript in the browser
You are affected if your FortiOS version is 5.2 through 5.4.12, 5.6.0 through 5.6.7, or 6.0.0 through 6.0.4, OR your FortiProxy version is 1.2.8 or below or exactly 2.0.0, AND the SSL VPN web portal is enabled with unsanitized input reflected in error/message handling parameters.
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.
From vendor dataUpgrade FortiOS to version 6.0.5 or later (or 5.6.8+, 5.4.13+) and FortiProxy to version 1.2.9 or later (or 2.0.1+). As a temporary workaround, consider restricting SSL VPN web portal access or implementing WAF rules to filter malicious script payloads.
Fix this in Fortios
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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 locallyCheck whether your project pulls in CVE-2018-13380 — 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-2018-13380 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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