Big Ip Local Traffic ManagerApplication · F5
CVE-2019-6686
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 · uneditedOn BIG-IP versions 15.0.0-15.0.1.1, 14.1.0-14.1.2, 14.0.0-14.0.1, 13.1.0-13.1.3.1, the Traffic Management Microkernel (TMM) might stop responding after the total number of diameter connections and pending messages on a single virtual server has reached 32K.
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 confidenceThe Traffic Management Microkernel (TMM) in affected BIG-IP versions can become unresponsive when diameter protocol connections and pending messages on a single virtual server reach approximately 32,000, causing a denial of service condition.
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
Big Ip Local Traffic ManagerApplication
>= 13.1.0, < 13.1.3.2>= 14.0.0, < 14.0.1.1>= 14.1.0, < 14.1.2.1>= 15.0.0, < 15.1.0CVSS 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
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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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Check BIG-IP software versionRun 'tmsh show sys version' or view the version in the web UI under System > Software Management > BIG-IP VersionAffected if The version falls within 13.1.0-13.1.3.2, 14.0.0-14.0.1.1, 14.1.0-14.1.2.1, or 15.0.0-15.1.0
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Identify virtual servers with DIAMETER protocol enabledRun 'tmsh list ltm virtual one-line' and look for 'profile diameter' in the output, or check via web UI under Local Traffic > Virtual Servers > Virtual Server ListAffected if Any virtual server has a DIAMETER profile applied (the vulnerability only triggers when DIAMETER is in use)
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Verify DIAMETER connection count on affected virtual serversRun 'tmsh show ltm virtual <virtual_name> statistics' and examine the 'diameter' connection counters, or use 'tmsh show ltm profile diameter' to view connection metricsAffected if The pending DIAMETER messages or concurrent connections on a single virtual server approach or exceed approximately 32,000
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Review TMM resource utilizationRun 'tmsh show sys tmm-info' and 'tmsh show sys tmm-statistics' to check for TMM issues or run 'tmsh show ltm virtual' to observe if DIAMETER virtual servers show abnormally high message queue depthsAffected if TMM is unresponsive or DIAMETER virtual servers show message queue buildup near the 32K threshold
The system is affected if it runs a vulnerable BIG-IP version AND has DIAMETER protocol enabled on virtual servers, with connection/message counts approaching 32,000 on any single DIAMETER virtual server.
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 data13.1.3.214.0.1.114.1.2.1
Upgrade BIG-IP to a fixed version beyond 15.0.1.1, 14.1.2, 14.0.1, or 13.1.3.1; alternatively, implement connection and message rate limiting on affected diameter virtual servers to prevent reaching the 32K threshold.
Fix this in Big Ip Local Traffic Manager
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-6686 — 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-2019-6686 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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