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Big Ip Advanced Web Application FirewallApplication · F5

CVE-2024-21849

HIGH · 7.5 CVSS v3.1 Published 2024-02-14
Fix available
A fix is available. Upgrade to 16.1.4 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
When an Advanced WAF/ASM security policy and a Websockets profile are configured on a virtual server, undisclosed traffic can cause the Traffic Management Microkernel (TMM) process 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 · moderate confidence

This is a denial-of-service vulnerability in F5 BIG-IP where the Traffic Management Microkernel (TMM) process terminates when a virtual server has both an Advanced WAF/ASM security policy and a Websockets profile configured. Specific undisclosed traffic triggers the crash, causing service disruption.

MitigationRemove either the Advanced WAF/ASM security policy or the Websockets profile from affected virtual servers until an official patch is available, or upgrade to a supported version receiving security updates.

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 Advanced Web Application FirewallApplication
Affected:>= 16.1.0, < 16.1.4
Big Ip Application Security ManagerApplication
Affected:>= 16.1.0, < 16.1.4

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 software version
    Run 'tmsh show /sys version' or view the web UI under Dashboard > Software Management to determine the installed BIG-IP version
    Affected if Version is 16.1.0, 16.1.1, 16.1.2, or 16.1.3 (versions below 16.1.4 in the 16.1.x branch)
  2. Identify virtual servers with security policies
    Run 'tmsh list /ltm virtual all-properties' and look for 'policy' entries under each virtual server configuration, or use the web UI under Local Traffic > Virtual Servers to review applied policies
    Affected if Any virtual server has an Advanced WAF or ASM security policy assigned
  3. Identify virtual servers with Websocket profiles
    Run 'tmsh list /ltm profile websocket' to list all websocket profiles, then cross-reference with virtual servers using 'tmsh list /ltm virtual all-properties' to see which virtual servers reference a websocket profile
    Affected if Any virtual server has a Websocket profile applied
  4. Cross-check for combined configuration
    Review the output from steps 2 and 3 to determine if any single virtual server has BOTH a security policy AND a websocket profile simultaneously applied
    Affected if At least one virtual server has both an Advanced WAF/ASM policy and a Websocket profile enabled at the same time

If the BIG-IP version is 16.1.0 through 16.1.3 and any virtual server has both a security policy and websocket profile configured, the environment is vulnerable to TMM crashes from this CVE.

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 16.1.4 or later
Fixed in 16.1.4
Interim mitigation

Remove either the Advanced WAF/ASM security policy or the Websockets profile from affected virtual servers until an official patch is available, or upgrade to a supported version receiving security updates.

Recommended fix High confidence

BIG-IP 16.1.4 or later (16.1.x stable releases)

  1. 1. Confirm current BIG-IP version is between 16.1.0 and 16.1.3 using 'tmsh show sys version'
  2. 2. Review F5 BIG-IP 16.1.4 release notes at my.f5.com for changes and any special upgrade considerations
  3. 3. Create a full UCS backup of the current configuration using 'tmsh save sys ucs <filename>'
  4. 4. Download BIG-IP 16.1.4 or later from F5 Downloads (my.f5.com)
  5. 5. Upload the ISO image to the BIG-IP and install using 'tmsh install sys software' or through the web UI (System > Software Management > ISO Image)
  6. 6. Boot to the new version and verify all services, especially TMM and ASM/AWAF, are running
  7. 7. Confirm the Advanced WAF/ASM security policy with Websockets profile no longer causes TMM termination
Caveat Review 16.1.4 release notes for any changes to Advanced WAF/ASM behavior or Websockets processing; test in non-production first

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

Fix this in Big Ip Advanced Web Application Firewall Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

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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-2024-21849 in production — separate from our analysis above.

No notes yet

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