CVE-2018-11458
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 has been identified in SINUMERIK 828D V4.7 (All versions < V4.7 SP6 HF1), SINUMERIK 840D sl V4.7 (All versions < V4.7 SP6 HF5), SINUMERIK 840D sl V4.8 (All versions < V4.8 SP3). The integrated VNC server on port 5900/tcp of the affected products could allow a remote attacker to execute code with privileged permissions on the system by sending specially crafted network requests to port 5900/tcp. Please note that this vulnerability is only exploitable if port 5900/tcp is manually opened in the firewall configuration of network port X130. The security vulnerability could be exploited by an attacker with network access to the affected devices and port. Successful exploitation requires no privileges and no user interaction. The vulnerability could allow an attacker to compromise confidentiality, integrity and availability of the VNC server. At the time of advisory publication no public exploitation of this security vulnerability was known.
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 remote code execution vulnerability exists in the integrated VNC server (port 5900/tcp) of Siemens SINUMERIK 828D and 840D sl CNC systems. An unauthenticated attacker with network access to the exposed VNC port can execute code with privileged permissions. The vulnerability is only exploitable if port 5900/tcp has been manually opened in the firewall configuration of network port X130.
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<= 4.7<= 4.7<= 4.8CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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 Sinumerik modelAccess the system HMI or use system information commands to determine if the device is a Sinumerik 828D or 840D slAffected if The device is not a 828D or 840D sl model - this CVE does not apply to other Siemens products
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Check the firmware versionAccess system diagnostics or version information to determine the installed firmware version (V4.7 or V4.8)Affected if The installed firmware version is 4.7 or lower for 828D, or 4.7/4.8 or lower for 840D sl - these are within the affected version ranges
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Verify if VNC server is enabledCheck system configuration or services to determine if the integrated VNC server is currently enabled on the systemAffected if VNC server is disabled - the vulnerability cannot be exploited without an active VNC service
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Check if port 5900/tcp is listeningPerform a port scan or use netstat commands to check if port 5900/tcp is open and listening on the deviceAffected if Port 5900 is not listening - the VNC service may not be active or the port is not exposed
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Verify firewall configuration for port 5900 on X130Review the firewall rules for network port X130 to determine if port 5900/tcp has been manually opened in the firewall configurationAffected if Port 5900/tcp is explicitly opened in the firewall configuration for network port X130 - this is the specific condition required for the vulnerability to be exploitable from the network
The environment is affected if it is a Sinumerik 828D or 840D sl running firmware V4.7 or lower (828D) or V4.7/V4.8 or lower (840D sl), with the VNC server enabled and port 5900/tcp exposed on network port X130.
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 vendor patches to reach V4.7 SP6 HF1 (828D), V4.7 SP6 HF5 or V4.8 SP3 (840D sl), and ensure port 5900/tcp is not exposed or is properly firewalled on network port X130.
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2018-11458 — 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-2018-11458 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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