What’s Vulnerable › Vulnerabilities

CVE-2018-5521

• Severity: medium (CVSS 6.1 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-06-01 · updated 2026-06-17
• Weakness: CWE-79

Description

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.

Affected products

• F5 BIG-IP APM: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• BIG-IP: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 Big-Ip Analytics: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 Networks, Inc. BIG-IP (AAM): from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• BIG-IP ASM: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 BIG-IP DNS: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 Big-Ip Edge Gateway: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 Big-Ip Global Traffic Manager: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 Big-Ip Link Controller: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 BIG-IP (LTM): from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 Networks, Inc. BIG-IP (PEM): from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 Big-Ip Webaccelerator: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1
• F5 Big-Ip Websafe: from 11.5.1 through 11.5.5; from 11.6.1 through 11.6.3; from 12.1.0 through 12.1.3; 11.2.1

References

• http://www.securitytracker.com/id/1041021
• https://support.f5.com/csp/article/K23124150
• http://www.securitytracker.com/id/1041021
• https://support.f5.com/csp/article/K23124150

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