CVE-2017-9938
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 vulnerability was discovered in Siemens SIMATIC Logon (All versions before V1.6) that could allow specially crafted packets sent to the SIMATIC Logon Remote Access service on port 16389/tcp to cause a Denial-of-Service condition. The service restarts automatically.
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 · moderate confidenceA denial-of-service vulnerability exists in Siemens SIMATIC Logon versions prior to V1.6. An unauthenticated attacker can send specially crafted packets to the SIMATIC Logon Remote Access service on port 16389/tcp, causing the service to crash. The service auto-restarts after the DoS condition.
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<= 1.5CVSS 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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Confirm SIMATIC Logon installationCheck for Siemens SIMATIC Logon in Windows installed programs (Add/Remove Programs) or look for the installation directory (typically under C:\Program Files\Siemens\SIMATIC Logon or C:\Program Files (x86)\Siemens\SIMATIC Logon)Affected if SIMATIC Logon is found on the system
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Identify installed versionLocate the SIMATIC Logon version by checking the executable properties (right-click on SIMATIC Logon.exe or similar executable in the installation folder, then view Details tab for version information), or check in Windows registry under HKLM\SOFTWARE\Siemens\SIMATIC LogonAffected if Version is 1.5 or lower (any version prior to V1.6)
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Verify port 16389/tcp exposureRun netstat -an | findstr 16389 or use PowerShell command Get-NetTCPConnection -LocalPort 16389 to check if port 16389 is listening, or scan the system with nmap -p 16389 localhostAffected if Port 16389/tcp is in LISTENING state and accessible
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Check Remote Access service statusOpen Windows Services console (services.msc) and locate the SIMATIC Logon Remote Access service, or check via command: sc query SIMATICLogonRemoteAccessAffected if The Remote Access service is running and enabled to start automatically
System is affected if SIMATIC Logon version 1.5 or lower is installed AND the Remote Access service on port 16389/tcp is exposed and running.
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 SIMATIC Logon to version V1.6 or later. If immediate patching is not feasible, consider network segmentation to restrict access to port 16389/tcp and monitor for anomalous traffic patterns.
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-9938 — 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-2017-9938 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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- Version or environment caveats, and links to real fixes
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