CVE-2018-14663
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 · uneditedAn issue has been found in PowerDNS DNSDist before 1.3.3 allowing a remote attacker to craft a DNS query with trailing data such that the addition of a record by dnsdist, for example an OPT record when adding EDNS Client Subnet, might result in the trailing data being smuggled to the backend as a valid record while not seen by dnsdist. This is an issue when dnsdist is deployed as a DNS Firewall and used to filter some records that should not be received by the backend. This issue occurs only when either the 'useClientSubnet' or the experimental 'addXPF' parameters are used when declaring a new backend.
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 confidenceIn dnsdist before 1.3.3, when adding records like OPT for EDNS Client Subnet, trailing data in maliciously crafted DNS queries can be passed through to the backend server while remaining invisible to dnsdist's filtering logic. This allows attackers to bypass DNS Firewall rules and send filtered record types to backend servers.
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<= 1.3.2CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.0/AV:N/AC:H/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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Determine installed dnsdist versionRun 'dnsdist --version' or check the package manager (e.g., 'rpm -q dnsdist' or 'dpkg -l dnsdist') to identify the exact version installed.Affected if The version is 1.3.2 or earlier (any version <= 1.3.2).
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Identify if DNS Firewall rules are in useInspect the dnsdist configuration file (typically /etc/dnsdist.conf or /etc/dnsdist/dnsdist.conf) and look for DNSFirewall, addAction, or related rule definitions that filter DNS record types.Affected if DNS Firewall rules that filter specific record types are configured and active.
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Check if useClientSubnet is enabledSearch the dnsdist configuration for 'useClientSubnet' or 'setUseClientSubnet' directives. This can be verified by running 'dnsdist -c' and querying the console if remote management is enabled, or by reviewing the configuration file.Affected if The useClientSubnet parameter is set to true or enabled in the configuration.
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Check if addXPF is enabledSearch the dnsdist configuration for 'addXPF' or 'setAddXPF' directives. This can also be verified through the dnsdist console if remote management is configured.Affected if The addXPF parameter is set to true or enabled in the configuration.
A user is affected if they run dnsdist version 1.3.2 or earlier with DNS Firewall rules configured AND either useClientSubnet or addXPF is enabled, allowing malicious queries with trailing data to bypass filtering.
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 dnsdist to version 1.3.3 or later. If immediate upgrade is not possible, audit filtering rules and consider disabling useClientSubnet and addXPF parameters until the upgrade can be performed.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2018-14663 — 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-2018-14663 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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