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Big Ip Access Policy ManagerApplication · F5

CVE-2020-5935

MEDIUM · 5.9 CVSS v3.1 Published 2020-10-29
Fix available
A fix is available. Upgrade to 13.1.3.4 / 14.1.2.4 or later.
See remediation →
68/100
Remediation priority · Elevated
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 (LTM, AAM, AFM, Analytics, APM, ASM, DNS, FPS, GTM, Link Controller, PEM) versions 15.1.0-15.1.0.5, 14.1.0-14.1.2.3, and 13.1.0-13.1.3.3, when handling MQTT traffic through a BIG-IP virtual server associated with an MQTT profile and an iRule performing manipulations on that traffic, TMM may produce a core file.

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

When BIG-IP handles MQTT traffic through a virtual server configured with both an MQTT profile and an iRule that performs manipulations on that traffic, the TMM (Traffic Management Module) may crash and produce a core file, resulting in a denial-of-service condition.

MitigationUpgrade BIG-IP to a version beyond 15.1.0.5, 14.1.2.3, or 13.1.3.3; alternatively, avoid using iRules that manipulate MQTT traffic in combination with MQTT profiles until patching is feasible.

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, < 13.1.3.4>= 14.1.0, < 14.1.2.4>= 15.0.0, < 15.1.1
Big Ip Advanced Firewall ManagerApplication
Affected:>= 13.1.0, < 13.1.3.4>= 14.1.0, < 14.1.2.4>= 15.0.0, < 15.1.1
Big Ip AnalyticsApplication
Affected:>= 13.1.0, < 13.1.3.4>= 14.1.0, < 14.1.2.4>= 15.0.0, < 15.1.1
Big Ip Application Acceleration ManagerApplication
Affected:>= 13.1.0, < 13.1.3.4>= 14.1.0, < 14.1.2.4>= 15.0.0, < 15.1.1
Big Ip Application Security ManagerApplication
Affected:>= 13.1.0, < 13.1.3.4>= 14.1.0, < 14.1.2.4>= 15.0.0, < 15.1.1
Big Ip Domain Name SystemApplication
Affected:>= 13.1.0, < 13.1.3.4>= 14.1.0, < 14.1.2.4>= 15.0.0, < 15.1.1
Big Ip Fraud Protection ServiceApplication
Affected:>= 13.1.0, < 13.1.3.4>= 14.1.0, < 14.1.2.4>= 15.0.0, < 15.1.1
Big Ip Global Traffic ManagerApplication
Affected:>= 13.1.0, < 13.1.3.4>= 14.1.0, < 14.1.2.4>= 15.0.0, < 15.1.1

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
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:H/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 'bigpipe version' to obtain the installed version
    Affected if The version falls within 13.1.0 to 13.1.3.3, 14.1.0 to 14.1.2.3, or 15.0.0 to 15.1.0.4
  2. Identify virtual servers with MQTT profile
    Run 'tmsh list ltm virtual profiles' to list virtual servers and their assigned profiles; look for 'mqtt' in the profile list
    Affected if Any virtual server has an MQTT profile assigned
  3. Find iRules on virtual servers with MQTT profile
    Run 'tmsh list ltm virtual <virtual_name> rules' for each virtual server that has an MQTT profile; inspect each iRule content using 'tmsh list ltm rule <rule_name>'
    Affected if An iRule assigned to a virtual server with an MQTT profile contains MQTT-related commands such as MQTT::, CLIENT_DATA, or MESSAGE
  4. Confirm MQTT traffic manipulation exists
    Review iRule code for any manipulations on MQTT messages including MQTT header modifications, message type changes, or payload alterations
    Affected if The iRule performs any write, modify, or manipulation operations on MQTT traffic or messages

You are affected if your BIG-IP version is within the vulnerable range AND you have a virtual server configured with both an MQTT profile and an iRule that manipulates MQTT 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
Upgrade available Upgrade to 13.1.3.4 / 14.1.2.4 / 15.1.1 or later
Fixed in 13.1.3.414.1.2.415.1.1
Interim mitigation

Upgrade BIG-IP to a version beyond 15.1.0.5, 14.1.2.3, or 13.1.3.3; alternatively, avoid using iRules that manipulate MQTT traffic in combination with MQTT profiles until patching is feasible.

Fix this in Big Ip Access Policy Manager Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

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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-2020-5935 in production — separate from our analysis above.

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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
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  • No spam, self-promotion, credentials, or personal data