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Big Ip Access Policy ManagerApplication · F5

CVE-2020-5949

HIGH · 7.5 CVSS v3.1 Published 2020-12-11
Fix available
A fix is available. Upgrade to 13.1.3.5 / 14.1.0 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 versions 14.0.0-14.0.1 and 13.1.0-13.1.3.4, certain traffic pattern sent to a virtual server configured with an FTP profile can cause the FTP channel to break.

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

In F5 BIG-IP versions 14.0.0-14.0.1 and 13.1.0-13.1.3.4, a specific traffic pattern sent to a virtual server configured with an FTP profile can cause the FTP data channel to break, resulting in a denial of service for FTP connections.

MitigationUpgrade BIG-IP to a version later than 14.0.1 (for 14.x) or later than 13.1.3.4 (for 13.1.x), or apply relevant hotfixes. Alternatively, consider removing the FTP profile from virtual servers if not required.

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:>= 13.1.0, < 13.1.3.5>= 14.0.0, < 14.1.0
Big Ip Advanced Firewall ManagerApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.0.0, < 14.1.0
Big Ip Advanced Web Application FirewallApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.0.0, < 14.1.0
Big Ip AnalyticsApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.0.0, < 14.1.0
Big Ip Application Acceleration ManagerApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.0.0, < 14.1.0
Big Ip Application Security ManagerApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.0.0, < 14.1.0
Big Ip Ddos Hybrid DefenderApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.0.0, < 14.1.0
Big Ip Domain Name SystemApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.0.0, < 14.1.0

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. Check BIG-IP version
    Run 'tmsh show /sys version' or view System > Software Management > Image List in the web UI to determine the installed BIG-IP version.
    Affected if Version is 13.1.0-13.1.3.4 or 14.0.0-14.0.1 (or falls within these ranges for the specific module)
  2. Identify FTP profiles configured
    Run 'tmsh list /ltm profile ftp' to list all FTP profiles, or navigate to Local Traffic > Profiles > FTP in the web UI.
    Affected if Any FTP profiles exist in the configuration
  3. Check virtual servers using FTP profiles
    Run 'tmsh list /ltm virtual' and inspect the 'profile' or 'profiles' section for ftp entries, or review virtual server settings in the web UI under Local Traffic > Virtual Servers.
    Affected if Any virtual server has an FTP profile assigned

You are affected if your BIG-IP version is 13.1.0-13.1.3.4 or 14.0.0-14.0.1 AND at least one virtual server has an FTP profile configured.

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 13.1.3.5 / 14.1.0 or later
Fixed in 13.1.3.514.1.0
Interim mitigation

Upgrade BIG-IP to a version later than 14.0.1 (for 14.x) or later than 13.1.3.4 (for 13.1.x), or apply relevant hotfixes. Alternatively, consider removing the FTP profile from virtual servers if not required.

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
Get the upgrade done

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-2020-5949 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