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Big Ip Application Acceleration ManagerApplication · F5

CVE-2018-5521

MEDIUM · 6.1 CVSS v3.0 Published 2018-06-01
Fix available
A fix is available. Upgrade to after 12.1.3 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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 12.1.0-12.1.3.1, 11.6.1-11.6.3.1, 11.5.1-11.5.5, or 11.2.1, carefully crafted URLs can be used to reflect arbitrary content into GeoIP lookup responses, potentially exposing clients to XSS.

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

The F5 BIG-IP GeoIP lookup feature does not properly sanitize user-supplied input in URLs, allowing arbitrary content to be reflected into the response. This reflected XSS vulnerability could allow attackers to execute malicious JavaScript in the context of victims' browsers when they interact with crafted URLs.

MitigationUpdate to a patched F5 BIG-IP version as specified in F5 advisory, or temporarily disable the GeoIP lookup feature if updating is not immediately 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 Application Acceleration ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.3>= 12.1.0, <= 12.1.3= 11.2.1
Big Ip Local Traffic ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.3>= 12.1.0, <= 12.1.3= 11.2.1
Big Ip Advanced Firewall ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.3>= 12.1.0, <= 12.1.3= 11.2.1
Big Ip AnalyticsApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.3>= 12.1.0, <= 12.1.3= 11.2.1
Big Ip Access Policy ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.3>= 12.1.0, <= 12.1.3= 11.2.1
Big Ip Application Security ManagerApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.3>= 12.1.0, <= 12.1.3= 11.2.1
Big Ip Domain Name SystemApplication
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.3>= 12.1.0, <= 12.1.3= 11.2.1
Big Ip Edge GatewayWeb browser
Affected:>= 11.5.1, <= 11.5.5>= 11.6.1, <= 11.6.3>= 12.1.0, <= 12.1.3= 11.2.1

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
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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 the installed BIG-IP version
    Run 'tmsh show /sys version' on the command line, or check the version displayed in the web UI footer, or inspect /etc/product_version
    Affected if The version falls within 11.2.1, 11.5.1-11.5.5, 11.6.1-11.6.3, or 12.1.0-12.1.3
  2. Locate active GeoIP profiles
    In the web UI, navigate to Local Traffic > Profiles > GeoIP, or run 'tmsh list ltm profile geo-ip' via command line to list all GeoIP profiles configured on the system
    Affected if Any GeoIP profile exists and is assigned to a virtual server
  3. Identify iRules using GeoIP lookup commands
    Run 'tmsh list ltm rule all' and search for 'geo' or 'GEO' commands such as 'class match', 'findclass', or '-geo' pool selection that reference the GeoIP database
    Affected if Any iRule contains GeoIP lookup commands and is applied to a virtual server
  4. Check for GeoIP database file presence
    Inspect the directory /shared/lib/GeoIP.dat or /var/GeoIP/ for the presence of a MaxMind GeoIP database file
    Affected if A GeoIP database file is present and the system is using the GeoIP feature

A system is affected if it runs a vulnerable BIG-IP version AND has the GeoIP lookup feature enabled (via profiles, iRules, or other configurations) that could reflect URL parameters into responses.

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

Update to a patched F5 BIG-IP version as specified in F5 advisory, or temporarily disable the GeoIP lookup feature if updating is not immediately feasible.

Fix this in Big Ip Application Acceleration Manager Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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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-2018-5521 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