CVE-2020-5941: F5 BIG-IP Access Policy Manager

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

On BIG-IP versions 16.0.0-16.0.0.1 and 15.1.0-15.1.0.5, using the RESOLV::lookup command within an iRule may cause the Traffic Management Microkernel (TMM) to generate a core file and restart. This issue occurs when data exceeding the maximum limit of a hostname passes to the RESOLV::lookup command.

Affected products

• F5 BIG-IP Access Policy Manager: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Advanced Firewall Manager: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Analytics: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Application Acceleration Manager: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Application Security Manager: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Domain Name System: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Fraud Protection Service: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Global Traffic Manager: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Link Controller: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Local Traffic Manager: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)
• F5 BIG-IP Policy Enforcement Manager: from 15.1.0, before 15.1.1 (fixed in 15.1.1); from 16.0.0, before 16.0.1 (fixed in 16.0.1)

Published 2020-11-05. Last modified 2026-06-17.