Debian LinuxOperating system · Debian
CVE-2016-7068
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 before 3.4.11 and 4.0.2, and PowerDNS recursor before 3.7.4 and 4.0.4, allowing a remote, unauthenticated attacker to cause an abnormal CPU usage load on the PowerDNS server by sending crafted DNS queries, which might result in a partial denial of service if the system becomes overloaded. This issue is based on the fact that the PowerDNS server parses all records present in a query regardless of whether they are needed or even legitimate. A specially crafted query containing a large number of records can be used to take advantage of that behaviour.
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 confidencePowerDNS (authoritative server and recursor) parses all DNS records in incoming queries regardless of whether they are needed or legitimate. A remote, unauthenticated attacker can send specially crafted DNS queries containing a large number of records to cause abnormal CPU usage, potentially leading to partial denial of service.
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
Debian LinuxOperating system
= 8.0< 3.4.11>= 4.0.0, < 4.0.2< 3.7.4>= 4.0.0, < 4.0.4CVSS 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 PowerDNS productRun 'dpkg -l | grep -i powerdns' or 'rpm -qa | grep -i powerdns' to list installed PowerDNS packages. Look for 'pdns' (authoritative server) or 'pdns-recursor' in the package names.Affected if Either pdns or pdns-recursor package is installed
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Determine PowerDNS versionRun 'pdns --version' for the authoritative server or 'pdns_recursor --version' for the recursor. Alternatively, use 'dpkg -l <package-name>' or 'rpm -q <package-name>' to get the installed package version.Affected if Version is < 3.4.11 for authoritative; OR >= 4.0.0 AND < 4.0.2 for authoritative; OR < 3.7.4 for recursor; OR >= 4.0.0 AND < 4.0.4 for recursor
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Verify DNS service is network accessibleCheck if PowerDNS is listening on port 53 with 'netstat -tulpn | grep :53' or 'ss -tulpn | grep :53'. Review firewall rules to confirm UDP/TCP port 53 is open to external sources.Affected if The DNS service accepts queries from untrusted network sources (not restricted to localhost or trusted IPs)
The system is affected if PowerDNS Authoritative (< 3.4.11 or >= 4.0.0 to < 4.0.2) or PowerDNS Recursor (< 3.7.4 or >= 4.0.0 to < 4.0.4) is running and reachable from untrusted networks.
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 data3.4.113.7.44.0.2
Upgrade PowerDNS to version 3.4.11 or later (4.0.2+) for the authoritative server, or 3.7.4 or later (4.0.4+) for the recursor. Consider implementing query rate limiting or filtering at network edge as a compensating control.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-7068 — 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-2016-7068 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
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data