dbcve.org
Big Ip Domain Name SystemApplication · F5

CVE-2021-23032

HIGH · 7.5 CVSS v3.1 Published 2021-09-14
Fix available
A fix is available. Upgrade to 14.1.4.4 / 15.1.3.1 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 version 16.x before 16.1.0, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.4, and all versions of 13.1.x and 12.1.x, when a BIG-IP DNS system is configured with non-default Wide IP and pool settings, undisclosed DNS responses can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

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

Denial of service vulnerability in F5 BIG-IP DNS where specific undisclosed DNS responses, when the system is configured with non-default Wide IP and pool settings, can cause the Traffic Management Microkernel (TMM) to terminate, resulting in service disruption.

MitigationUpgrade BIG-IP DNS to version 16.1.0 or later, 15.1.3.1 or later, or 14.1.4.4 or later to resolve the vulnerability. Note that 13.1.x and 12.1.x branches have no fix and require upgrade to a supported version.

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 Domain Name SystemApplication
Affected:>= 12.1.0, <= 12.1.6>= 13.1.0, <= 13.1.4>= 14.1.0, < 14.1.4.4>= 15.1.0, < 15.1.3.1>= 16.0.0, < 16.1.0

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. Check BIG-IP DNS version
    Run `tmsh show sys version` or `bigpipe version` to obtain the installed BIG-IP version. Compare it against the affected ranges: 12.1.0-12.1.6, 13.1.0-13.1.4, 14.1.0-14.1.4.3, 15.1.0-15.1.3.0, and 16.0.0-16.1.0.
    Affected if The installed version falls within any of the affected ranges listed above.
  2. Verify DNS module is active
    Run `tmsh show gtmd` or check the DNS profile status via `tmsh list ltm dns` to confirm the BIG-IP DNS service is enabled and processing traffic.
    Affected if The DNS module is enabled and the version is vulnerable.
  3. Inspect Wide IP configuration
    Run `tmsh list gtm wideip` to list all Wide IP configurations. Look for any Wide IP entries that are configured beyond default settings.
    Affected if Any non-default Wide IP configuration exists on the system.
  4. Inspect GTM pool settings
    Run `tmsh list gtm pool` to review GTM/DNS pool configurations. Check for pool settings that deviate from defaults.
    Affected if Non-default pool settings are configured.

The environment is affected if the BIG-IP DNS version is within the vulnerable ranges AND the system has non-default Wide IP and pool settings configured, allowing the vulnerability to be triggered by malicious DNS responses.

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.

dbcve · scoped
Upgrade available Upgrade to 14.1.4.4 / 15.1.3.1 / 16.1.0 or later
Fixed in 14.1.4.415.1.3.116.1.0
Interim mitigation

Upgrade BIG-IP DNS to version 16.1.0 or later, 15.1.3.1 or later, or 14.1.4.4 or later to resolve the vulnerability. Note that 13.1.x and 12.1.x branches have no fix and require upgrade to a supported version.

Recommended fix High confidence

14.1.4.4 (or later), 15.1.3.1 (or later), or 16.1.0 (or later) depending on version branch

  1. 1. Identify the current Big-IP DNS version by running `tmsh show sys version` or checking the web UI.
  2. 2. Determine which version branch your current installation is on (12.1.x, 13.1.x, 14.1.x, or 15.1.x).
  3. 3. For 14.1.x versions: Upgrade to version 14.1.4.4 or later.
  4. 4. For 15.1.x versions: Upgrade to version 15.1.3.1 or later.
  5. 5. For 16.x versions: Upgrade to version 16.1.0 or later.
  6. 6. Note: Versions 12.1.x and 13.1.x have reached End of Technical Support (EoTS) and do not have patches; migration to a supported version is required.
  7. 7. After upgrade, verify TMM is running with `tmsh show sys tmm-status` and confirm DNS functionality.
Caveat Upgrading major versions may introduce configuration or compatibility changes; review F5 release notes before upgrading. Versions 12.1.x and 13.1.x require migration to a supported version as they are EoTS.

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

Fix this in Big Ip Domain Name System Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,480
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,968.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-23032 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-23032 in production — separate from our analysis above.

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