Big Ip Local Traffic ManagerApplication · F5
CVE-2020-5936
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 · uneditedOn BIG-IP LTM 15.1.0-15.1.0.5, 14.1.0-14.1.2.7, 13.1.0-13.1.3.4, and 12.1.0-12.1.5.1, the Traffic Management Microkernel (TMM) process may consume excessive resources when processing SSL traffic and client authentication are enabled on the client SSL profile.
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 confidenceIn F5 BIG-IP LTM, the Traffic Management Microkernel (TMM) consumes excessive resources when processing SSL traffic with client authentication enabled on client SSL profiles, leading to potential denial of service. The vulnerability affects specific versions across 12.1.x, 13.1.x, 14.1.x, and 15.1.x branches.
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
>= 12.1.0, < 12.1.5.2>= 13.1.0, <= 13.1.3.4>= 14.1.0, < 14.1.2.8>= 15.0.0, < 15.1.1CVSS 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 checksWork through these to decide whether this CVE applies to you.
-
Check BIG-IP versionRun command 'tmsh show /sys version' or inspect file /etc/neokme/VERSION to obtain the installed BIG-IP versionAffected if Version falls within the affected ranges: 12.1.0 through 12.1.5.1, 13.1.0 through 13.1.3.4, 14.1.0 through 14.1.2.7, or 15.0.0 through 15.1.0
-
Identify client SSL profilesRun 'tmsh list /ltm profile client-ssl all-properties' to list all configured client SSL profiles on the BIG-IP deviceAffected if Any client SSL profiles exist in the configuration
-
Verify client certificate authentication is enabledFor each client SSL profile, check if the 'client-cert-ca' or equivalent client certificate authentication setting is configured and enabled (not set to 'none' or disabled)Affected if Client certificate authentication is enabled on any client SSL profile
-
Confirm active virtual servers use affected profilesRun 'tmsh list /ltm virtual' and cross-reference with the client SSL profiles from step 2 to determine if any virtual servers are using client-authenticating SSL profilesAffected if Any virtual server references a client SSL profile with client certificate authentication enabled
The environment is affected if the BIG-IP version is within the vulnerable ranges AND there exists a client SSL profile with client certificate authentication enabled that is in use by a virtual server.
Generated from the published advisory. Verify against your own configuration.
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 data12.1.5.214.1.2.815.1.1
Upgrade to a patched version beyond 15.1.0.5, 14.1.2.7, 13.1.3.4, or 12.1.5.1; alternatively, disable client certificate authentication on affected SSL profiles if not required for the application.
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
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-5936 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-5936 in production — separate from our analysis above.
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.
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.
- 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