Traffic ControlApplication · Apache
CVE-2017-7670
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 Traffic Router component of the incubating Apache Traffic Control project is vulnerable to a Slowloris style Denial of Service attack. TCP connections made on the configured DNS port will remain in the ESTABLISHED state until the client explicitly closes the connection or Traffic Router is restarted. If connections remain in the ESTABLISHED state indefinitely and accumulate in number to match the size of the thread pool dedicated to processing DNS requests, the thread pool becomes exhausted. Once the thread pool is exhausted, Traffic Router is unable to service any DNS request, regardless of transport protocol.
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 confidenceApache Traffic Control's Traffic Router is vulnerable to a Slowloris-style Denial of Service attack where TCP connections on the DNS port remain in ESTABLISHED state indefinitely, exhausting the thread pool dedicated to DNS request processing and preventing legitimate DNS queries from being serviced.
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
Traffic ControlApplication
<= 1.8.0= 1.8.1= 2.0.0CVSS 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
- 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 Traffic Router versionCheck the installed version of Apache Traffic Control's Traffic Router component. This is typically found in the RPM/DEB package name, or by querying the Traffic Router service with its management interface if available.Affected if The installed version is 1.8.0, 1.8.1, or 2.0.0 (or any version <= 1.8.0)
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Confirm DNS service is enabledVerify that Traffic Router's DNS service port (typically port 53) is enabled and listening for incoming connections. Check the Traffic Router configuration files for DNS-related settings.Affected if DNS service is enabled and exposed on a network interface accessible to potential attackers
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Inspect active TCP connections to DNS portUse netstat or ss commands to list all TCP connections in ESTABLISHED state on the DNS port (port 53). Run: netstat -an | grep :53 | grep ESTABLISHED or ss -tan state established dport = :53Affected if There are TCP connections to the DNS port remaining in ESTABLISHED state for extended periods without being closed
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Review DNS thread pool exhaustionMonitor Traffic Router logs and system resources to determine if DNS request processing threads are fully utilized. Check if legitimate DNS queries are timing out or failing.Affected if The DNS thread pool is exhausted and legitimate DNS queries cannot be serviced
You are affected if you are running Traffic Router version 1.8.0, 1.8.1, or 2.0.0 with the DNS service enabled and exposed, and you observe stalled ESTABLISHED connections on the DNS port causing query failures.
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 connection timeouts and rate limiting on the DNS port to prevent indefinite connection hold states, and consider increasing thread pool size or implementing per-client connection limits as temporary mitigations until the fix is applied.
Fix this in Traffic Control
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 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 $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-7670 — 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-2017-7670 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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