Big Ip Access Policy ManagerApplication · F5
CVE-2020-5919
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 · uneditedIn versions 15.1.0-15.1.0.4, rendering of certain session variables by BIG-IP APM UI-based agents in an access profile configured with Modern customization, may cause the Traffic Management Microkernel (TMM) to stop responding.
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 confidenceA denial of service vulnerability in BIG-IP APM allows UI-based agents with Modern customization to render certain session variables in a way that causes the Traffic Management Microkernel (TMM) to stop responding. This affects access profiles using Modern customization type in versions 15.1.0 through 15.1.0.4.
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 Access Policy ManagerApplication
>= 15.1.0, < 15.1.0.5CVSS 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.
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Check BIG-IP versionRun `tmsh show sys version` or view version in the web UI under Diagnostics > SupportAffected if Version is 15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, or 15.1.0.4
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Verify APM module is provisionedCheck via web UI under System > Resource Provisioning, or run `tmsh list sys provision apm`Affected if APM module shows as provisioned (any level)
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Identify access profiles using Modern customizationIn the web UI, go to Access Policy > Access Profiles List and check the Customization Type column for each profileAffected if Any access profile has Customization Type set to Modern
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Check for UI-based access policy agentsEdit each access profile using Modern customization and review the access policy visual policy editor for agents that render session variables (such as Logon Page, Message Box, or similar UI-rendering agents)Affected if A Modern customization access policy contains UI-based agents that process session variables
A user is affected if their BIG-IP runs version 15.1.0 to 15.1.0.4, has APM provisioned, and uses an access profile with Modern customization type containing UI-based agents that render session variables.
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 data15.1.0.5
Upgrade BIG-IP to a version beyond 15.1.0.4, or modify the access profile customization settings to not use Modern customization.
Fix this in Big Ip Access Policy Manager
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-5919 — 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-2020-5919 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
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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