dbcve.org
Big Ip Local Traffic ManagerApplication · F5

CVE-2018-5531

HIGH · 7.4 CVSS v3.0 Published 2018-07-25
Fix available
A fix is available. Upgrade to after 13.1.0.7 or later.
See remediation →
79/100
Remediation priority · High
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
Through undisclosed methods, on F5 BIG-IP 13.0.0-13.1.0.7, 12.1.0-12.1.3.5, 11.6.0-11.6.3.1, or 11.2.1-11.5.6, adjacent network attackers can cause a denial of service for VCMP guest and host systems. Attack must be sourced from adjacent network (layer 2).

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

F5 BIG-IP systems running VCMP (Virtual Clustered Multiprocessing) contain a denial of service vulnerability exploitable from the adjacent network (layer 2). Attackers can crash both VCMP guest and host systems through undisclosed methods. The vulnerability affects specific version ranges across BIG-IP 13.x, 12.x, 11.6.x, and 11.5.x platforms.

MitigationUpgrade F5 BIG-IP to a version beyond the affected releases (13.1.0.8+, 12.1.3.6+, 11.6.3.2+, or 11.5.7+) per F5 advisory. If immediate patching is not feasible, restrict layer 2 network access to trusted systems only.

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
Affected:>= 11.2.1, <= 11.5.6>= 11.6.0, <= 11.6.3.1>= 12.1.0, <= 12.1.3.5>= 13.0.0, <= 13.1.0.7
Big Ip Application Acceleration ManagerApplication
Affected:>= 11.2.1, <= 11.5.6>= 11.6.0, <= 11.6.3.1>= 12.1.0, <= 12.1.3.5>= 13.0.0, <= 13.1.0.7
Big Ip Advanced Firewall ManagerApplication
Affected:>= 11.2.1, <= 11.5.6>= 11.6.0, <= 11.6.3.1>= 12.1.0, <= 12.1.3.5>= 13.0.0, <= 13.1.0.7
Big Ip AnalyticsApplication
Affected:>= 11.2.1, <= 11.5.6>= 11.6.0, <= 11.6.3.1>= 12.1.0, <= 12.1.3.5>= 13.0.0, <= 13.1.0.7
Big Ip Access Policy ManagerApplication
Affected:>= 11.2.1, <= 11.5.6>= 11.6.0, <= 11.6.3.1>= 12.1.0, <= 12.1.3.5>= 13.0.0, <= 13.1.0.7
Big Ip Application Security ManagerApplication
Affected:>= 10.1.0, <= 11.5.6>= 11.6.0, <= 11.6.3.1>= 12.1.0, <= 12.1.3.5>= 13.0.0, <= 13.1.0.7
Big Ip Domain Name SystemApplication
Affected:>= 11.2.1, <= 11.5.6>= 11.6.0, <= 11.6.3.1>= 12.1.0, <= 12.1.3.5>= 13.0.0, <= 13.1.0.7
Big Ip Edge GatewayWeb browser
Affected:>= 11.2.1, <= 11.5.6>= 11.6.0, <= 11.6.3.1>= 12.1.0, <= 12.1.3.5>= 13.0.0, <= 13.1.0.7

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/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. Verify if VCMP is enabled on the BIG-IP system
    Run the command 'tmsh show vcmp info' or check the VCMP configuration via the web interface under Local Traffic > Virtual Clustered Multiprocessing. Look for the VcmpStatus field or active VCMP guests.
    Affected if VCMP is enabled or configured with active guests (the vulnerability affects systems with VCMP enabled)
  2. Check the installed BIG-IP version
    Run 'tmsh show sys version' or view the version in the web interface under System > Software Management > ISO Image. Note the exact version number (e.g., 13.1.0.7, 12.1.3.5, 11.6.3.1).
    Affected if The version falls within these ranges: 11.5.x up to 11.5.6, 11.6.0 through 11.6.3.1, 12.1.0 through 12.1.3.5, or 13.0.0 through 13.1.0.7
  3. Confirm network adjacency exposure
    Review the network topology to determine if the BIG-IP VCMP interfaces are accessible from untrusted layer 2 (adjacent) network segments. Check switch port configurations and VLAN membership for VCMP-related interfaces.
    Affected if The system is reachable from untrusted adjacent network segments at layer 2 (the exploit is triggered from the adjacent network)

The system is affected if VCMP is enabled, the BIG-IP version is within the vulnerable ranges listed, and the layer 2 network is accessible to untrusted actors.

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 a release after 13.1.0.7
Interim mitigation

Upgrade F5 BIG-IP to a version beyond the affected releases (13.1.0.8+, 12.1.3.6+, 11.6.3.2+, or 11.5.7+) per F5 advisory. If immediate patching is not feasible, restrict layer 2 network access to trusted systems only.

Fix this in Big Ip Local Traffic Manager Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-5531 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2018-5531 in production — separate from our analysis above.

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.

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