CVE-2025-1673
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 malicious or malformed DNS packet without a payload can cause an out-of-bounds read, resulting in a crash (denial of service) or an incorrect computation.
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 confidenceOut-of-bounds read vulnerability in DNS packet parsing logic when processing malformed DNS packets without a payload, allowing remote attackers to cause denial of service (crash) or incorrect computation.
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<= 4.0CVSS 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
- Low
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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 Zephyr OS is in useIdentify if the target system runs Zephyrproject Zephyr as its embedded OS. Check build artifacts, firmware metadata, or system documentation for 'Zephyr' or 'zephyr' references.Affected if The system does not run Zephyr OS - then this CVE does not apply
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Check Zephyr versionDetermine the installed Zephyr version from build configuration, SDK documentation, or firmware metadata. Compare against the affected range: versions <= 4.0.Affected if Running Zephyr version 4.0 or lower - falls within affected range
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Verify DNS functionality is enabledInspect the system configuration (devicetree, Kconfig, or build settings) to determine if the DNS client or DNS server module is compiled and active.Affected if DNS parsing code is not present or not executed - the vulnerability cannot be triggered
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Confirm network packet processing is activeCheck if the network stack is configured to process incoming DNS packets. Look for DNS port (53) listener or DNS resolver initialization in the runtime configuration.Affected if Network stack does not process DNS packets - the malformed packet trigger cannot reach the vulnerable code
If the system runs Zephyr <= 4.0 with DNS client or server functionality enabled and network packet processing active, it is affected by this out-of-bounds read vulnerability.
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 dataImplement proper bounds checking in DNS packet parsing to validate payload existence before memory access, and update to patched versions when available from vendors.
- Consultation3.0 h
- Implementation4.0 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 $3,648.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-1673 — 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-2025-1673 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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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