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Big Ip Local Traffic ManagerApplication · F5

CVE-2019-6643

HIGH · 7.5 CVSS v3.1 Published 2019-09-04
Fix available
A fix is available. Upgrade to after 13.1.1 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
On versions 14.1.0-14.1.0.5, 14.0.0-14.0.0.4, 13.0.0-13.1.2, 12.1.0-12.1.4.1, and 11.5.2-11.6.4, an attacker sending specifically crafted DHCPv6 requests through a BIG-IP virtual server configured with a DHCPv6 profile may be able to cause the TMM process to produce a core file.

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 confidence

F5 BIG-IP systems with a DHCPv6 profile configured on a virtual server are vulnerable to a denial-of-service condition. An attacker can send specially crafted DHCPv6 packets that cause the TMM (Traffic Management Microkernel) process to crash and produce a core file, resulting in service disruption.

MitigationUpgrade F5 BIG-IP to a version beyond 14.1.0.5, 14.0.0.4, 13.1.2, 12.1.4.1, or 11.6.4. If immediate patching is not possible, consider removing the DHCPv6 profile from exposed virtual servers or restricting access to those virtual 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
Big Ip Local Traffic ManagerApplication
Affected:>= 11.5.2, <= 11.6.4>= 12.1.0, <= 12.1.4>= 13.0.0, <= 13.1.1= 14.0.0= 14.1.0
Big Ip Advanced Firewall ManagerApplication
Affected:>= 11.5.2, <= 11.6.4>= 12.1.0, <= 12.1.4>= 13.0.0, <= 13.1.1= 14.0.0= 14.1.0
Big Ip Application Acceleration ManagerApplication
Affected:>= 11.5.2, <= 11.6.4>= 12.1.0, <= 12.1.4>= 13.0.0, <= 13.1.1= 14.0.0= 14.1.0
Big Ip AnalyticsApplication
Affected:>= 11.5.2, <= 11.6.4>= 12.1.0, <= 12.1.4>= 13.0.0, <= 13.1.1= 14.0.0= 14.1.0
Big Ip Access Policy ManagerApplication
Affected:>= 11.5.2, <= 11.6.4>= 12.1.0, <= 12.1.4>= 13.0.0, <= 13.1.1= 14.0.0= 14.1.0
Big Ip Application Security ManagerApplication
Affected:>= 11.5.2, <= 11.6.4>= 12.1.0, <= 12.1.4>= 13.0.0, <= 13.1.1= 14.0.0= 14.1.0
Big Ip Edge GatewayWeb browser
Affected:>= 11.5.2, <= 11.6.4>= 12.1.0, <= 12.1.4>= 13.0.0, <= 13.1.1= 14.0.0= 14.1.0
Big Ip Fraud Protection ServiceApplication
Affected:>= 11.5.2, <= 11.6.4>= 12.1.0, <= 12.1.4>= 13.0.0, <= 13.1.1= 14.0.0= 14.1.0

CVSS 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:3.1/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the BIG-IP version
    Run the command 'tmsh show sys version' or check the BIG-IP GUI under System > Software. Alternatively, run 'f5version' from the command line.
    Affected if The installed version falls within 11.5.2-11.6.4, 12.1.0-12.1.4, 13.0.0-13.1.1, 14.0.0, or 14.1.0.
  2. Locate virtual servers with DHCPv6 profiles
    Run 'tmsh list ltm virtual one-arm' for each virtual server and inspect the DHCPv6 profile configuration. From the GUI, navigate to Local Traffic > Virtual Servers and check the DHCPv6 profile assigned to each virtual server.
    Affected if A DHCPv6 profile is assigned to any virtual server.
  3. Check for TMM crash core files
    Inspect the directory /var/core/ for any core files with 'tmm' in the name using 'ls -la /var/core/ | grep tmm'. Also check for recent TMM restart events in /var/log/ltm.
    Affected if TMM core files exist or TMM crash events are logged.
  4. Verify DHCPv6 service status
    Run 'tmsh show ltm dns dhcpv6' to view DHCPv6 configuration and status. Check if the DHCPv6 daemon is running with 'tmsh show sys service dhcpd'.
    Affected if DHCPv6 profile is actively configured and the service is enabled.

A system is affected if it runs an affected BIG-IP version AND has a DHCPv6 profile configured on any virtual server, with TMM crashes being a confirmatory indicator.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Upgrade available Upgrade to a release after 13.1.1
Interim mitigation

Upgrade F5 BIG-IP to a version beyond 14.1.0.5, 14.0.0.4, 13.1.2, 12.1.4.1, or 11.6.4. If immediate patching is not possible, consider removing the DHCPv6 profile from exposed virtual servers or restricting access to those virtual servers.

Fix this in Big Ip Local Traffic Manager Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-6643 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data