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Big Ip Local Traffic ManagerApplication · F5

CVE-2018-5507

HIGH · 7.5 CVSS v3.0 Published 2018-04-13
Fix available
A fix is available. Upgrade to after 12.1.3 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 F5 BIG-IP versions 13.0.0, 12.1.0-12.1.3.1, 11.6.1-11.6.2, or 11.5.1-11.5.5, vCMP guests running on VIPRION 2100, 4200 and 4300 series blades cannot correctly decrypt ciphertext from established SSL sessions with small MTU.

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

On F5 BIG-IP VIPRION 2100, 4200, and 4300 series blades running vCMP guests, a bug exists where the guest cannot correctly decrypt ciphertext from established SSL sessions when the MTU is small. This is a cryptographic implementation flaw specific to the vCMP virtualization layer on these blade models.

MitigationApply the appropriate F5 hotfix or upgrade to a patched BIG-IP version outside the affected version ranges. Test SSL decryption functionality with reduced MTU values in the vCMP guest environment after patching.

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:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.2>= 12.1.0, <= 12.1.3= 13.0.0
Big Ip Application Acceleration ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.2>= 12.1.0, <= 12.1.3= 13.0.0
Big Ip Advanced Firewall ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.2>= 12.1.0, <= 12.1.3= 13.0.0
Big Ip AnalyticsApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.2>= 12.1.0, <= 12.1.3= 13.0.0
Big Ip Access Policy ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.2>= 12.1.0, <= 12.1.3= 13.0.0
Big Ip Application Security ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.2>= 12.1.0, <= 12.1.3= 13.0.0
Big Ip Edge GatewayWeb browser
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.2>= 12.1.0, <= 12.1.3= 13.0.0
Big Ip Global Traffic ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.2>= 12.1.0, <= 12.1.3= 13.0.0

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
High
Integrity
None
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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. Identify hardware platform
    Run command 'tmsh show sys hardware' or check the console boot screen to determine if the device is a VIPRION 2100, 4200, or 4300 series blade.
    Affected if The hardware is a VIPRION 2100, 4200, or 4300 blade - only these models are affected.
  2. Check if vCMP is enabled
    Run 'tmsh show vcmp' or review the vCMP configuration via 'tmsh list vcmp' to determine if vCMP guests are provisioned.
    Affected if vCMP virtualization is not running - the flaw only affects vCMP guests on the vulnerable blade models.
  3. Determine BIG-IP version
    Run 'tmsh show sys version' or check the version displayed in the BIG-IP configuration utility under System > Software Information.
    Affected if The installed version falls within these ranges: 11.5.1-11.5.5, 11.6.1-11.6.2, 12.1.0-12.1.3, or 13.0.0 - only versions in these ranges are affected.
  4. Check MTU configuration in vCMP guests
    Run 'tmsh list net interface' and 'tmsh list net vlan' within each vCMP guest to inspect the MTU settings, or check the physical interface MTU on the host for vCMP traffic.
    Affected if A small MTU value is configured - the cryptographic flaw triggers specifically when MTU is small enough to fragment SSL traffic.

You are affected only if you are running a vulnerable BIG-IP version on a VIPRION 2100/4200/4300 blade with vCMP guests and small MTU values 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 a release after 12.1.3
Interim mitigation

Apply the appropriate F5 hotfix or upgrade to a patched BIG-IP version outside the affected version ranges. Test SSL decryption functionality with reduced MTU values in the vCMP guest environment after patching.

Fix this in Big Ip Local Traffic Manager Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,750
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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-2018-5507 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data