CVE-2018-16994
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 · uneditedAn issue was discovered on PHOENIX CONTACT AXL F BK PN <=1.0.4, AXL F BK ETH <= 1.12, and AXL F BK ETH XC <= 1.11 devices and Bosch Rexroth S20-ETH-BK and Rexroth S20-PN-BK+ (the S20-PN-BK+/S20-ETH-BK fieldbus couplers sold by Bosch Rexroth contain technology from Phoenix Contact). Incorrect handling of a request with non-standard symbols allows remote attackers to initiate a complete lock up of the bus coupler. Authentication of the request is not required.
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 confidenceThis is a denial-of-service vulnerability in Phoenix Contact and Bosch Rexroth fieldbus couplers. The devices incorrectly handle network requests containing non-standard symbols, allowing unauthenticated remote attackers to trigger a complete lockup of the bus coupler by sending specially crafted requests.
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<= 1.0.4<= 1.12<= 1.11CVSS 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 the fieldbus coupler modelLocate the physical device or check network inventory for device hostname, MAC OUI, or model designation. Look for device identifiers containing 'AXL F BK PN', 'AXL F BK ETH', or 'AXL F BK ETH XC'.Affected if The device model is a Phoenix Contact AXL F BK PN, AXL F BK ETH, or AXL F BK ETH XC fieldbus coupler.
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Retrieve the installed firmware versionAccess the device web interface, console, or management interface and navigate to the firmware/version information section. Alternatively, use SNMP, the vendor's management software, or network scanning tools that can query the device for its firmware version string.Affected if The installed firmware version is <= 1.0.4 for AXL F BK PN, <= 1.12 for AXL F BK ETH, or <= 1.11 for AXL F BK ETH XC.
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Verify network accessibility of the deviceConfirm the device has an IP address and is reachable on the network by pinging it or checking network scan results. Determine if the device is directly exposed to untrusted networks or behind appropriate firewall segmentation.Affected if The device is network-accessible and can receive malformed network requests from attackers.
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Check for device lockup symptomsMonitor network logs or perform a test ping to verify the device is currently responsive. Look for signs of previous lockup events in network monitoring systems or incident logs.Affected if The device has become unresponsive or exhibits intermittent connectivity issues consistent with a lockup condition.
A user is affected if they have a Phoenix Contact AXL F BK PN (firmware <=1.0.4), AXL F BK ETH (firmware <=1.12), or AXL F BK ETH XC (firmware <=1.11) fieldbus coupler that is network-accessible.
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 available firmware updates from the vendors (AXL F BK PN >=1.0.5, AXL F BK ETH >=1.13, AXL F BK ETH XC >=1.12, and corresponding Bosch Rexroth patches). If patches are unavailable, isolate these devices behind firewalls and implement network monitoring to detect exploitation attempts.
- Consultation8.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-16994 — 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-2018-16994 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
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