CVE-2023-27334
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 · uneditedSofting edgeConnector Siemens ConditionRefresh Resource Exhaustion Denial-of-Service Vulnerability. This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Softing edgeConnector Siemens. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of OPC UA ConditionRefresh requests. By sending a large number of requests, an attacker can consume all available resources on the server. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-20498.
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 confidenceSofting edgeConnector Siemens suffers from a resource exhaustion vulnerability in its OPC UA ConditionRefresh request handling. An unauthenticated remote attacker can send a large volume of ConditionRefresh requests to consume all available server resources, causing a denial-of-service 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< 3.70< 3.70< 6.20.1< 1.30CVSS 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 installed Softing product and versionLocate the product documentation, installation directory, or check the application itself for its version number. For Edgeaggregator, Edgeconnector, or Secure Integration Server, check the main application or service information.Affected if Version is lower than 3.70 for Edgeaggregator/Edgeconnector, lower than 6.20.1 for OPC UA C++ SDK, or lower than 1.30 for Secure Integration Server
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Confirm OPC UA server is running and exposedCheck if the Softing OPC UA server service is active and listening on network ports (typically OPC UA ports such as 4840, or configured custom ports). Use netstat or equivalent to identify listening services.Affected if OPC UA server is running and accessible on the network, enabling external ConditionRefresh requests to reach it
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Verify ConditionRefresh endpoint accessibilityCheck OPC UA server configuration or endpoint security settings to determine if ConditionRefresh operations are permitted. Review OPC UA client access permissions or anonymous authentication status.Affected if Anonymous or unauthenticated access to the OPC UA server is allowed, making the ConditionRefresh endpoint reachable by remote attackers
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Monitor for resource exhaustion symptomsObserve server CPU, memory, and network connection usage. Check for unusually high connection counts or request volumes that could indicate a ConditionRefresh-based resource exhaustion attack.Affected if Server exhibits high resource consumption or connection saturation that correlates with OPC UA ConditionRefresh request activity
A user is affected if they are running any of the listed Softing products with a version below the specified thresholds and their OPC UA server is accessible to unauthenticated remote attackers who can send ConditionRefresh requests.
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.
dbcve · scoped1.303.706.20.1
Implement rate limiting, request throttling, or connection quotas on the OPC UA ConditionRefresh endpoint to prevent resource exhaustion. Consider adding request timeouts and monitoring for anomalous request volumes.
Edgeaggregator/Edgeconnector: 3.70+ | Opc Ua C++ SDK: 6.20.1+ | Secure Integration Server: 1.30+
- 1. Identify all affected Softing products in your environment (Edgeaggregator, Edgeconnector, OPC UA C++ SDK, Secure Integration Server)
- 2. Check current installed versions of each product
- 3. For Edgeaggregator and Edgeconnector: upgrade to version 3.70 or later
- 4. For OPC UA C++ Software Development Kit: upgrade to version 6.20.1 or later
- 5. For Secure Integration Server: upgrade to version 1.30 or later
- 6. After upgrade, verify the OPC UA ConditionRefresh functionality works correctly
- 7. Test that the resource consumption issue is resolved by attempting normal ConditionRefresh operations
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-27334 — 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-2023-27334 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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