Big Ip Link ControllerApplication · F5

CVE-2019-6675

CRITICAL · 9.8 CVSS v3.1 Published 2019-11-26

Fix available

A fix is available. Upgrade to after 15.0.1.0.48.11-eng_hotfix or later.

See remediation →

100/100

Remediation priority · Urgent

Remotely reachable No privileges Zero-click

Official description

NVD · unedited

BIG-IP configurations using Active Directory, LDAP, or Client Certificate LDAP for management authentication with multiple servers are exposed to a vulnerability which allows an authentication bypass. This can result in a complete compromise of the system. This issue only impacts specific engineering hotfixes using the aforementioned authentication configuration. NOTE: This vulnerability does not affect any of the BIG-IP major, minor or maintenance releases you obtained from downloads.f5.com. The affected Engineering Hotfix builds are as follows: Hotfix-BIGIP-14.1.0.3.0.79.6-ENG.iso, Hotfix-BIGIP-14.1.0.3.0.97.6-ENG.iso, Hotfix-BIGIP-14.1.0.3.0.99.6-ENG.iso, Hotfix-BIGIP-14.1.0.5.0.15.5-ENG.iso, Hotfix-BIGIP-14.1.0.5.0.36.5-ENG.iso, Hotfix-BIGIP-14.1.0.5.0.40.5-ENG.iso, Hotfix-BIGIP-14.1.0.6.0.11.9-ENG.iso, Hotfix-BIGIP-14.1.0.6.0.14.9-ENG.iso, Hotfix-BIGIP-14.1.0.6.0.68.9-ENG.iso, Hotfix-BIGIP-14.1.0.6.0.70.9-ENG.iso, Hotfix-BIGIP-14.1.2.0.11.37-ENG.iso, Hotfix-BIGIP-14.1.2.0.18.37-ENG.iso, Hotfix-BIGIP-14.1.2.0.32.37-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.46.4-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.14.4-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.16.4-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.34.4-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.97.4-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.99.4-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.105.4-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.111.4-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.115.4-ENG.iso, Hotfix-BIGIP-14.1.2.1.0.122.4-ENG.iso, Hotfix-BIGIP-15.0.1.0.33.11-ENG.iso, Hotfix-BIGIP-15.0.1.0.48.11-ENG.iso

Technical summary

dbcve analysis · high confidence

F5 BIG-IP systems configured with Active Directory, LDAP, or Client Certificate LDAP for management authentication using multiple servers contain an authentication bypass vulnerability in specific engineering hotfix builds. An unauthenticated remote attacker can bypass authentication mechanisms and gain full administrative access to the system, resulting in complete compromise.

MitigationApply a F5-provided patch or migrate from affected engineering hotfixes to standard BIG-IP releases from downloads.f5.com. If the affected hotfix configuration is required, contact F5 for specific fixed hotfix builds.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

Big Ip Link ControllerApplication

Affected:>= 15.0.1.0.33.11-eng_hotfix, <= 15.0.1.0.48.11-eng_hotfix= 14.1.0.3.0.79.6-eng_hotfix= 14.1.0.3.0.97.6-eng_hotfix= 14.1.0.3.0.99.6-eng_hotfix= 14.1.0.5.0.15.5-eng_hotfix= 14.1.0.5.0.36.5-eng_hotfix= 14.1.0.5.0.40.5-eng_hotfix= 14.1.0.6.0.11.9-eng_hotfix= 14.1.0.6.0.14.9-eng_hotfix= 14.1.0.6.0.68.9-eng_hotfix= 14.1.0.6.0.70.9-eng_hotfix= 14.1.2.0.11.37-eng_hotfix

Big Ip Access Policy ManagerApplication

Big Ip Advanced Firewall ManagerApplication

Big Ip Application Acceleration ManagerApplication

Big Ip Application Security ManagerApplication

Big Ip Fraud Protection ServiceApplication

Big Ip Local Traffic ManagerApplication

Big Ip Policy Enforcement ManagerApplication

CVSS breakdown

From the vector

Attack vector: Network
Complexity: Low
Privileges: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected?

dbcve checks

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

Obtain the BIG-IP system version

Run 'tmsh show sys version' or check the BIG-IP GUI under Dashboard > System > Software Version to retrieve the installed version string.

Affected if The version contains 'eng_hotfix' and falls within 15.0.1.0.33.11 to 15.0.1.0.48.11, or matches any of the listed 14.1.0.x eng_hotfix versions (0.79.6, 0.97.6, 0.99.6, 0.15.5, 0.36.5, 0.40.5, 0.11.9, 0.14.9, 0.68.9, 0.70.9, or 0.11.37).
Confirm the product module

Identify which BIG-IP module is in use (LTM, APM, ASM, AFM, Link Controller, AAM, FPS, or PEM) from the installed license or by running 'tmsh show sys license' and reviewing the 'Module' field.

Affected if The product is any of the affected modules listed in the CVE (all modules share the same affected version list).
Check management authentication configuration

Run 'tmsh list auth password' and 'tmsh list auth ldap' or access the GUI under System > Users > Authentication to verify the configured authentication type for management access.

Affected if The system is configured to use Active Directory, LDAP, or Client Certificate LDAP for management authentication with multiple servers defined.
Verify multiple authentication servers exist

Review the LDAP or Active Directory configuration details to confirm whether more than one authentication server is specified in the management authentication setup.

Affected if Multiple authentication servers are configured in the AD/LDAP/Client Certificate LDAP authentication realm used for management.

The system is affected if it runs an engineering hotfix version matching the specific eng_hotfix build numbers AND is configured with AD, LDAP, or Client Certificate LDAP authentication using multiple servers for management access.

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

Remediation

dbcve · scoped

Upgrade available Upgrade to a release after 15.0.1.0.48.11-eng_hotfix

Interim mitigation

Apply a F5-provided patch or migrate from affected engineering hotfixes to standard BIG-IP releases from downloads.f5.com. If the affected hotfix configuration is required, contact F5 for specific fixed hotfix builds.

Recommended fix High confidence

Upgrade to any standard BIG-IP maintenance release (e.g., 14.1.0, 14.1.1, 14.1.2, 15.0.1, or later) from downloads.f5.com - these releases are not affected by this vulnerability

1. Identify the current BIG-IP engineering hotfix version in use by running 'tmsh show sys version' or checking the GUI system information.
2. Confirm the system uses Active Directory, LDAP, or Client Certificate LDAP for management authentication with multiple servers configured.
3. If the system is on an affected engineering hotfix (14.1.0.3.0.79.6, 14.1.0.3.0.97.6, 14.1.0.3.0.99.6, 15.0.1.0.33.11 through 15.0.1.0.48.11, or other hotfixes listed in the official description), plan an upgrade.
4. Download and install a standard BIG-IP maintenance release from downloads.f5.com (e.g., 14.1.0 GA, 14.1.1, 14.1.2, 15.0.1 GA, or later) instead of an engineering hotfix.
5. After upgrade, verify management authentication is functioning correctly for all configured authentication methods.
6. Review and test all Active Directory, LDAP, and Client Certificate LDAP authentication configurations.

Caveat Engineering hotfixes may contain specific custom fixes; ensure required functionality is preserved in the standard release

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Big Ip Link Controller Scoped from the published advisory

Consultation4.0 h
Implementation8.0 h
Testing4.0 h
Review / QA2.0 h

18.0 hours of engineering $3,200

Get the upgrade done

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Scan for this in your stack

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References

Primary sources

support.f5.comVendor Advisory
support.f5.com
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-6675 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2019-6675?

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

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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
No weaponised exploit code, or anything meant to cause harm
No spam, self-promotion, credentials, or personal data

At a glance

A fix existsUpgrade to after 15.0.1.0.48.11-eng_hotfix or later

Severity 9.8 Critical

Exploit likelihood EPSS, next 30 days 0.9%

Affects: Big Ip Link Controller

Remediation

A high-priority fix

Fix this in Big Ip Link Controller 18 hrs · Moderate

Typical engagement from $3,200

Get a fix See the full breakdown ↓

A high-priority vulnerability. Send your environment and a specialist will scope CVE-2019-6675 and return a fixed quote and timeline.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

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.

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.

Check your environment

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.

Scan for this in your stack

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

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References