dbcve.org
Big Ip WebsafeApplication · F5

CVE-2016-7476

HIGH · 7.5 CVSS v3.0 Published 2017-05-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
The Traffic Management Microkernel (TMM) in F5 BIG-IP LTM, AAM, AFM, APM, ASM, GTM, Link Controller, PEM, PSM, and WebSafe 11.6.0 before 11.6.0 HF6, 11.5.0 before 11.5.3 HF2, and 11.3.0 before 11.4.1 HF10 may suffer from a memory leak while handling certain types of TCP traffic. Remote attackers may cause a denial of service (DoS) by way of a crafted TCP packet.

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

A memory leak exists in the F5 BIG-IP Traffic Management Microkernel (TMM) component. Remote attackers can trigger this vulnerability by sending specially crafted TCP packets, causing memory exhaustion and resulting in denial of service.

MitigationApply the appropriate F5 hotfix: HF6 for version 11.6.0, HF2 for version 11.5.3, or HF10 for version 11.4.1. Alternatively, upgrade to a supported version beyond the affected releases.

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 WebsafeApplication
Affected:= 11.6.0
Big Ip Protocol Security ModulePlugin / extension
Affected:= 11.3.0= 11.4.0= 11.4.1
Big Ip Policy Enforcement ManagerApplication
Affected:= 11.3.0= 11.4.0= 11.4.1= 11.5.0= 11.5.1= 11.5.2= 11.5.3= 11.6.0
Big Ip Link ControllerApplication
Affected:= 11.3.0= 11.4.0= 11.4.1= 11.5.0= 11.5.1= 11.5.2= 11.5.3= 11.6.0
Big Ip Global Traffic ManagerApplication
Affected:= 11.3.0= 11.4.0= 11.4.1= 11.5.0= 11.5.1= 11.5.2= 11.5.3= 11.6.0
Big Ip Application Security ManagerApplication
Affected:= 11.3.0= 11.4.0= 11.4.1= 11.5.0= 11.5.1= 11.5.2= 11.5.3= 11.6.0
Big Ip Access Policy ManagerApplication
Affected:= 11.3.0= 11.4.0= 11.4.1= 11.5.0= 11.5.1= 11.5.2= 11.5.3= 11.6.0
Big Ip Advanced Firewall ManagerApplication
Affected:= 11.3.0= 11.4.0= 11.4.1= 11.5.0= 11.5.1= 11.5.2= 11.5.3= 11.6.0

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:3.0/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 version
    Run 'tmsh show sys version' or access the web UI under System > Software Management > BIG-IP Version to view the installed version.
    Affected if The version matches 11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, or 11.6.0.
  2. Identify active modules
    Run 'tmsh list sys module' or check System > Resource Overview in the web UI to see which F5 modules are licensed and running.
    Affected if Any of these modules are enabled: Websafe, Protocol Security Module, Policy Enforcement Manager, Link Controller, Global Traffic Manager, Application Security Manager, Access Policy Manager, or Advanced Firewall Manager.
  3. Verify TMM is active
    Run 'tmsh show sys tmm' to confirm the Traffic Management Microkernel is running. The vulnerability exists in the TMM component.
    Affected if TMM is active and processing traffic.
  4. Check memory usage
    Run 'tmsh show sys memory' or monitor TMM memory via the web UI under Statistics > Module Statistics > Traffic Management Microkernel. Look for abnormally high memory consumption.
    Affected if Memory usage is unexpectedly high or growing continuously without returning to baseline.

You are affected if your BIG-IP runs version 11.3.0 through 11.6.0, has any of the vulnerable modules enabled, and TMM is actively processing traffic.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the appropriate F5 hotfix: HF6 for version 11.6.0, HF2 for version 11.5.3, or HF10 for version 11.4.1. Alternatively, upgrade to a supported version beyond the affected releases.

Fix this in Big Ip Websafe Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,720
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2016-7476 — 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-2016-7476 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