CVE-2023-4489
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 · uneditedThe first S0 encryption key is generated with an uninitialized PRNG in Z/IP Gateway products running Silicon Labs Z/IP Gateway SDK v7.18.3 and earlier. This makes the first S0 key generated at startup predictable, potentially allowing network key prediction and unauthorized S0 network access.
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 confidenceThe Z/IP Gateway SDK uses a PRNG to generate S0 encryption keys for network security. The first S0 key is generated at startup with an uninitialized PRNG, meaning the random seed is not properly established. This causes the first generated key to be predictable rather than cryptographically random, potentially allowing attackers to derive the network key and gain unauthorized access to the S0 network.
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<= 7.18.03CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/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 installed Z/IP Gateway SDK versionLocate the SDK version file or check the product installation directory for version information. Common locations include the SDK release notes, a version.txt file, or the application properties/logs showing the SDK build version.Affected if The installed version is 7.18.03 or earlier (any version <= 7.18.03)
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Confirm S0 network security is in useReview the Z/IP Gateway configuration files (typically stored in the gateway's config directory) to determine if S0 security is enabled for Z-Wave network communication.Affected if S0 security mode is enabled in the gateway configuration, as the vulnerability only affects S0 encryption key generation
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Verify first S0 key was generated at startupCheck the gateway logs or key storage location for evidence that an S0 key was generated during the initial startup sequence of the Z/IP Gateway.Affected if The first S0 network key was generated since the flaw specifically affects only the first key produced after startup when the PRNG is uninitialized
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Inspect PRNG initialization in gateway logsReview Z/IP Gateway startup logs for any indicators of PRNG state or initialization messages related to cryptographic random number generation.Affected if Logs show the first S0 key was generated at initial startup before the PRNG was fully initialized with proper entropy
A user is affected if they are running Z/IP Gateway SDK version 7.18.03 or earlier with S0 security enabled, and their first S0 network key was generated during initial startup before the PRNG was properly seeded.
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 dataUpdate to Silicon Labs Z/IP Gateway SDK v7.18.4 or later to obtain the fixed PRNG initialization, then regenerate all S0 network keys to ensure the network is protected with truly random keys.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-4489 — 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-2023-4489 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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