CVE-2023-3825
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 · uneditedPTC’s KEPServerEX Versions 6.0 to 6.14.263 are vulnerable to being made to read a recursively defined object that leads to uncontrolled resource consumption. KEPServerEX uses OPC UA, a protocol which defines various object types that can be nested to create complex arrays. It does not implement a check to see if such an object is recursively defined, so an attack could send a maliciously created message that the decoder would try to decode until the stack overflowed and the device crashed.
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 confidenceKEPServerEX Versions 6.0-6.14.263 OPC UA server lacks validation for recursively defined objects in the decoder. An attacker can send maliciously crafted OPC UA messages containing nested objects that reference themselves, causing the decoder to recursively process until stack exhaustion and crash the service.
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>= 6.0.0, <= 6.14.263CVSS 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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Confirm KEPServerEX installationCheck the Windows Programs and Features list, or look for the installation directory (typically C:\Program Files\Kepware\KEPServerEX V6\) and locate the version info in the executable properties or release notes.Affected if KEPServerEX is not installed on the system.
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Identify installed KEPServerEX versionOpen the KEPServerEX Configuration dialog, go to Help > About, or check the executable properties of KEPServerEX.exe. Compare the version number against the affected range 6.0.0 to 6.14.263.Affected if The installed version falls within 6.0.0 through 6.14.263 inclusive.
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Verify OPC UA server is enabledOpen KEPServerEX Configuration, expand the project tree, and check if any OPC UA server driver ( Kepware OPC UA Server) is added and configured with an endpoint.Affected if An OPC UA server is enabled and configured with an active endpoint.
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Check OPC UA network exposureReview the OPC UA server endpoint binding settings in the KEPServerEX Configuration. Determine if the endpoint is bound to a non-localhost interface or is accessible over the network.Affected if The OPC UA endpoint is accessible from non-localhost addresses (network-exposed).
A system is affected if KEPServerEX version 6.0.0-6.14.263 is installed with an OPC UA server enabled and network-accessible, allowing untrusted OPC UA clients to send malicious recursive object messages.
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 patch (version 6.14.264 or later). If immediate patching is not possible, restrict OPC UA network access to trusted clients and implement rate limiting on OPC UA endpoints to limit attack surface.
- Consultation2.0 h
- Implementation1.0 h
- Testing4.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-3825 — 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-2023-3825 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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