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Big Ip Access Policy ManagerApplication · F5

CVE-2020-5856

HIGH · 7.5 CVSS v3.1 Published 2020-02-06
Fix available
A fix is available. Upgrade to 14.1.2.3 / 15.1.0 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 BIG-IP 15.0.0-15.0.1.1 and 14.1.0-14.1.2.2, while processing specifically crafted traffic using the default 'xnet' driver, Virtual Edition instances hosted in Amazon Web Services (AWS) may experience a TMM restart.

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 denial-of-service vulnerability exists in F5 BIG-IP Virtual Edition instances running on AWS. When processing specially crafted network traffic through the default 'xnet' driver, a TMM (Traffic Management Microkernel) restart occurs, causing service interruption.

MitigationUpgrade BIG-IP to a version beyond 15.0.1.1 for 15.x or beyond 14.1.2.2 for 14.x. If immediate patching is not feasible, consider restricting traffic sources or implementing additional filtering at the AWS security group level.

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
Affected:>= 14.1.0, < 14.1.2.3>= 15.0.0, < 15.1.0
Big Ip Advanced Firewall ManagerApplication
Affected:>= 14.1.0, < 14.1.2.3>= 15.0.0, < 15.1.0
Big Ip AnalyticsApplication
Affected:>= 14.1.0, < 14.1.2.3>= 15.0.0, < 15.1.0
Big Ip Application Acceleration ManagerApplication
Affected:>= 14.1.0, < 14.1.2.3>= 15.0.0, < 15.1.0
Big Ip Application Security ManagerApplication
Affected:>= 14.1.0, < 14.1.2.3>= 15.0.0, < 15.1.0
Big Ip Domain Name SystemApplication
Affected:>= 14.1.0, < 14.1.2.3>= 15.0.0, < 15.1.0
Big Ip Fraud Protection ServiceApplication
Affected:>= 14.1.0, < 14.1.2.3>= 15.0.0, < 15.1.0
Big Ip Global Traffic ManagerApplication
Affected:>= 14.1.0, < 14.1.2.3>= 15.0.0, < 15.1.0

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. Confirm BIG-IP is running on AWS
    Check the cloud platform where BIG-IP is deployed. On the BIG-IP command line, run 'tmsh show sys cloud' or verify through AWS console that the instance is an EC2 instance running the BIG-IP VE image.
    Affected if The instance is not deployed on AWS, this specific vulnerability does not apply.
  2. Verify the product is Virtual Edition
    Run 'tmsh show sys hardware' and look for the platform type. Virtual Edition instances will show as 'Virtual Edition' or 'VE' in the output.
    Affected if The system is a hardware BIG-IP appliance (not Virtual Edition), the vulnerability does not apply.
  3. Check the installed BIG-IP version
    Run 'tmsh show sys version' or 'bigstart status' to display the installed version. Compare the version number to the affected ranges: 14.1.0 through 14.1.2.2, or 15.0.0 through 15.0.x.
    Affected if The version falls within 14.1.0 <= version < 14.1.2.3 OR 15.0.0 <= version < 15.1.0.
  4. Identify the network driver in use
    Run 'tmsh show sys tmm-info' or check the network configuration via 'tmsh list net interface' to determine which driver is assigned to the interfaces. The vulnerability specifically affects the default 'xnet' driver used on AWS VE instances.
    Affected if The system is using the 'xnet' driver (the default for AWS Virtual Edition deployments).

The environment is affected if it is a BIG-IP Virtual Edition deployed on AWS, running versions 14.1.0-14.1.2.2 or 15.0.0-15.0.x, and using the default xnet network driver.

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
Upgrade available Upgrade to 14.1.2.3 / 15.1.0 or later
Fixed in 14.1.2.315.1.0
Interim mitigation

Upgrade BIG-IP to a version beyond 15.0.1.1 for 15.x or beyond 14.1.2.2 for 14.x. If immediate patching is not feasible, consider restricting traffic sources or implementing additional filtering at the AWS security group level.

Fix this in Big Ip Access Policy Manager Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

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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-2020-5856 in production — separate from our analysis above.

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What this is

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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