FortiproxyApplication · Fortinet
CVE-2018-13381
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 buffer overflow vulnerability in Fortinet FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.7, 5.4 and earlier versions and FortiProxy 2.0.0, 1.2.8 and earlier versions under SSL VPN web portal allows a non-authenticated attacker to perform a Denial-of-service attack via special craft message payloads.
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 confidenceBuffer overflow vulnerability in Fortinet FortiOS and FortiProxy SSL VPN web portal allows unauthenticated attackers to send specially crafted message payloads that overflow a fixed-size buffer, causing denial of service. The vulnerability affects specific version ranges of both products.
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
FortiproxyApplication
<= 1.2.8= 2.0.0
FortiosOperating system
<= 5.2.14>= 5.4.0, <= 5.4.12>= 5.6.0, <= 5.6.10>= 6.0.0, <= 6.0.4CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Identify product and versionAccess the device CLI or web interface to determine if the product is FortiOS or FortiProxy and retrieve the installed firmware version. In CLI, this is typically shown by 'get system status' or similar version query commands.Affected if The product is FortiOS with version <= 5.2.14, 5.4.0 to 5.4.12, 5.6.0 to 5.6.10, or 6.0.0 to 6.0.4; OR the product is FortiProxy with version <= 1.2.8 or exactly 2.0.0
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Confirm SSL VPN web portal is enabledCheck the device configuration to verify whether the SSL VPN web portal feature is active. This can typically be verified through the web UI under SSL-VPN settings or via CLI commands that display SSL VPN configuration status.Affected if The SSL VPN web portal is enabled and accessible to network users
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Verify web portal accessibilityDetermine whether the SSL VPN web portal is exposed to untrusted networks or if access is restricted to trusted IP addresses only, as the vulnerability is exploitable by unauthenticated attackers sending specially crafted message payloads.Affected if The SSL VPN web portal is reachable from untrusted or external networks without IP-based access restrictions
You are affected if you are running a vulnerable FortiOS or FortiProxy version within the affected ranges AND the SSL VPN web portal is enabled and accessible to potential attackers.
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 dataApply Fortinet's patches for the affected FortiOS (6.0.5+, 5.6.8+, 5.4.10+) and FortiProxy versions; until patched, restrict SSL VPN web portal access to trusted IP addresses via firewall policies.
Fix this in Fortiproxy
Scoped from the published advisory
- Consultation4.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,160.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-13381 — 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-2018-13381 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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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.
- 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