CVE-2017-15107
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 was found in the implementation of DNSSEC in Dnsmasq up to and including 2.78. Wildcard synthesized NSEC records could be improperly interpreted to prove the non-existence of hostnames that actually exist.
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 confidenceDnsmasq's DNSSEC validation implementation has a flaw where wildcard-synthesized NSEC records are incorrectly interpreted, causing the validator to falsely prove that hostnames exist when they actually do (false negatives). This allows a malicious actor to potentially make legitimate hostnames appear non-existent to DNSSEC-validating clients.
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<= 2.78CVSS 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
- High
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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 Dnsmasq versionRun 'dnsmasq --version' to display the installed Dnsmasq version numberAffected if Version displayed is 2.78 or lower
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Verify DNSSEC validation is enabledInspect the dnsmasq configuration file (commonly /etc/dnsmasq.conf or /etc/dnsmasq.d/*.conf) for lines containing 'dnssec' or 'dnssec-check-unsigned'Affected if Configuration contains 'dnssec' directive enabling DNSSEC validation
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Confirm wildcard DNS records existReview DNS zone files served by this dnsmasq instance, or query the DNS server for known wildcard entries (e.g., *.example.com) using 'dig +dnssec'Affected if Wildcard records (such as *.domain.com) are present in the DNS zones and DNSSEC is enabled
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Test for false negative behaviorPerform DNSSEC-validated queries for legitimate hostnames covered by wildcards using 'dig +dnssec hostname.domain.com' and verify the AD (authentic data) flag; then cross-check with non-validating queries to confirm records actually existAffected if DNSSEC-validating queries return NXDOMAIN (non-existent) for hostnames that resolve correctly without DNSSEC validation
You are affected if running Dnsmasq version 2.78 or earlier with DNSSEC validation enabled and serving DNS zones containing wildcard records.
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 dataUpgrade Dnsmasq to version 2.79 or later which contains the fix. Prior to upgrade, assess current DNSSEC deployment and after upgrade, thoroughly test DNSSEC validation to ensure wildcard records are now correctly validated.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2017-15107 — 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-2017-15107 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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