CVE-2018-13994
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 · uneditedThe WebUI of PHOENIX CONTACT FL SWITCH 3xxx, 4xxx, 48xx versions 1.0 to 1.34 is vulnerable to a denial-of-service attack by making more than 120 connections.
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 confidenceThe WebUI component of Phoenix Contact FL SWITCH 3xxx, 4xxx, and 48xx industrial network switches (versions 1.0-1.34) lacks proper connection throttling, allowing an attacker to exhaust available connections by establishing more than 120 simultaneous HTTP connections, causing the WebUI to become unavailable.
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>= 1.0, <= 1.34>= 1.0, <= 1.34>= 1.0, <= 1.34>= 1.0, <= 1.34>= 1.0, <= 1.34>= 1.0, <= 1.34>= 1.0, <= 1.34>= 1.0, <= 1.34CVSS 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:3.0/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 the device modelAccess the device via console or network and check the model name, looking for FL SWITCH 3xxx, 4xxx, or 48xx series identifiers (such as FL SWITCH 3005, 3008, 3004t FX, etc.)Affected if The device is not a Phoenix Contact FL SWITCH 3xxx, 4xxx, or 48xx series switch
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Check the installed firmware versionLog into the device WebUI or use console access to navigate to System > Firmware Info or similar menu to retrieve the current firmware version numberAffected if The firmware version is 1.0 through 1.34 inclusive (versions outside this range or not readable are not affected)
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Verify the WebUI component is enabledCheck the device configuration to confirm the HTTP/HTTPS WebUI service is active and accessible on the networkAffected if The WebUI is disabled or not configured, as the vulnerability only affects the WebUI component
If the device is a Phoenix Contact FL SWITCH 3xxx/4xxx/48xx with firmware version 1.0-1.34 and the WebUI is enabled, the environment is affected by this connection exhaustion vulnerability.
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 firmware to version 1.35 or later. If immediate patching is not possible, restrict access to the WebUI via network segmentation or firewall rules to limit exposure to untrusted networks.
- Consultation4.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,728.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-13994 — 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-2018-13994 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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