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Big Ip Local Traffic ManagerApplication · F5

CVE-2018-5506

CRITICAL · 9.8 CVSS v3.0 Published 2018-04-13
Fix available
A fix is available. Upgrade to after 12.1.3.1 or later.
See remediation →
100/100
Remediation priority · Urgent
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
In F5 BIG-IP 13.0.0, 12.1.0-12.1.2, 11.6.1, 11.5.1-11.5.5, or 11.2.1 the Apache modules apache_auth_token_mod and mod_auth_f5_auth_token.cpp allow possible unauthenticated bruteforce on the em_server_ip authorization parameter to obtain which SSL client certificates used for mutual authentication between BIG-IQ or Enterprise Manager (EM) and managed BIG-IP devices.

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

F5 BIG-IP Apache modules apache_auth_token_mod and mod_auth_f5_auth_token.cpp contain an unauthenticated brute-force vulnerability on the em_server_ip authorization parameter, potentially allowing attackers to obtain SSL client certificates used for mutual authentication between BIG-IQ/Enterprise Manager and managed BIG-IP devices.

MitigationApply F5 security patches for affected BIG-IP versions (13.0.0, 12.1.0-12.1.2, 11.6.1, 11.5.1-11.5.5, 11.2.1) and restrict network access to management interfaces to limit exposure.

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>= 12.1.0, <= 12.1.3.1= 11.2.1= 11.6.1= 13.0.0
Big Ip Application Acceleration ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 12.1.0, <= 12.1.3.1= 11.2.1= 11.6.1= 13.0.0
Big Ip Advanced Firewall ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 12.1.0, <= 12.1.3.1= 11.2.1= 11.6.1= 13.0.0
Big Ip AnalyticsApplication
Affected:>= 11.5.1, <= 11.5.5>= 12.1.0, <= 12.1.3.1= 11.2.1= 11.6.1= 13.0.0
Big Ip Access Policy ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 12.1.0, <= 12.1.3.1= 11.2.1= 11.6.1= 13.0.0
Big Ip Application Security ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 12.1.0, <= 12.1.3.1= 11.2.1= 11.6.1= 13.0.0
Big Ip Edge GatewayWeb browser
Affected:>= 11.5.1, <= 11.5.5>= 12.1.0, <= 12.1.3.1= 11.2.1= 11.6.1= 13.0.0
Big Ip Global Traffic ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 12.1.0, <= 12.1.3.1= 11.2.1= 11.6.1= 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
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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. Identify installed BIG-IP version
    Run 'tmsh show /sys version' or 'bigpipe version' from the command line
    Affected if The reported version falls within 11.2.1, 11.5.1-11.5.5, 11.6.1, 12.1.0-12.1.3.1, or 13.0.0
  2. Confirm BIG-IP module in use
    Verify the system is running one of the affected modules: Local Traffic Manager (LTM), Application Acceleration Manager (AAM), Advanced Firewall Manager (AFM), Analytics, Access Policy Manager (APM), Application Security Manager (ASM), Edge Gateway, or Global Traffic Manager (GTM)
    Affected if Any of these modules are installed on a version from step 1 that falls within the affected ranges
  3. Check management interface exposure
    Review network access controls and determine if the BIG-IP management interface (GUI or iControl REST) is reachable from untrusted networks
    Affected if Management interface is accessible from external/untrusted networks, as the vulnerability is unauthenticated
  4. Verify Apache auth module presence
    Examine the Apache configuration for the presence of apache_auth_token_mod or mod_auth_f5_auth_token.cpp modules handling the em_server_ip parameter
    Affected if These Apache modules are loaded and handling the em_server_ip authorization parameter for BIG-IQ/Enterprise Manager communication

You are affected if your BIG-IP version matches any of the listed affected versions AND the management interface is network-accessible, allowing unauthenticated attackers to attempt brute-force attacks against the em_server_ip parameter in the Apache authentication modules.

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.

dbcve · scoped
Upgrade available Upgrade to a release after 12.1.3.1
Interim mitigation

Apply F5 security patches for affected BIG-IP versions (13.0.0, 12.1.0-12.1.2, 11.6.1, 11.5.1-11.5.5, 11.2.1) and restrict network access to management interfaces to limit exposure.

Recommended fix High confidence

11.5.6+ (for 11.5.x), 11.6.2+ (for 11.6.x), 12.1.3.2+ (for 12.1.x), or 13.1.0+ (for 13.x)

  1. 1. Identify the current BIG-IP version by running 'tmsh show sys version' or checking the web UI (System > Software > Image List)
  2. 2. Based on your current major version, plan upgrade to the following fixed releases: For 11.5.x branch, upgrade to 11.5.6 or later; For 11.6.x branch, upgrade to 11.6.2 or later; For 12.1.x branch, upgrade to 12.1.3.2 or later; For 13.x branch, upgrade to 13.1.0 or later
  3. 3. Download the appropriate hotfix ISO from the F5 downloads portal (https://downloads.f5.com) or obtain from F5 Customer Support
  4. 4. Back up the current configuration using 'tmsh save sys config' and verify the backup file is accessible
  5. 5. If using BIG-IQ or Enterprise Manager for management, ensure the upgrade is coordinated as the vulnerability affects mutual authentication between these components
  6. 6. Upload and install the hotfix via the web UI (Software Management > Image List > Upload) or via tmsh: 'tmsh install sys software hotfix <hotfix-name> volume <volume-name>'
  7. 7. Verify the installation completed successfully and reboot if required
  8. 8. After upgrade, confirm the system is running the fixed version with 'tmsh show sys version'
Caveat Standard BIG-IP upgrade considerations apply: verify compatibility with existing iRules, profiles, and third-party integrations; plan for brief service interruption during reboot; test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Big Ip Local Traffic Manager Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2018-5506 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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