CVE-2019-6683

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-12-23 · updated 2026-06-17
Weakness: CWE-400

Description

On versions 15.0.0-15.0.1.1, 14.1.0-14.1.2.2, 14.0.0-14.0.1, 13.1.0-13.1.3.2, 12.1.0-12.1.5, and 11.5.2-11.6.5.1, BIG-IP virtual servers with Loose Initiation enabled on a FastL4 profile may be subject to excessive flow usage under undisclosed conditions.

Affected products

F5 BIG-IP APM: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
BIG-IP: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 Big-Ip Analytics: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 Networks, Inc. BIG-IP (AAM): from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
BIG-IP ASM: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 BIG-IP DNS: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 Big-Ip Edge Gateway: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 Big-Ip Fraud Protection Service: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 Big-Ip Global Traffic Manager: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 Big-Ip Link Controller: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 BIG-IP (LTM): from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 Networks, Inc. BIG-IP (PEM): from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0
F5 Big-Ip Webaccelerator: from 11.5.2 through 11.6.5; from 12.1.0 through 12.1.5; from 13.1.0 through 13.1.3; from 14.0.0 before 14.0.1.1; from 14.1.0 before 14.1.2.3; from 15.0.0 before 15.1.0 — fixed in 14.0.1.1, 14.1.2.3, 15.1.0

How to fix

Upgrade to a fixed version: F5 BIG-IP APM 14.0.1.1, 14.1.2.3, 15.1.0; BIG-IP 14.0.1.1, 14.1.2.3, 15.1.0; F5 Big-Ip Analytics 14.0.1.1, 14.1.2.3, 15.1.0; F5 Networks, Inc. BIG-IP (AAM) 14.0.1.1, 14.1.2.3, 15.1.0; BIG-IP ASM 14.0.1.1, 14.1.2.3, 15.1.0; F5 BIG-IP DNS 14.0.1.1, 14.1.2.3, 15.1.0; F5 Big-Ip Edge Gateway 14.0.1.1, 14.1.2.3, 15.1.0; F5 Big-Ip Fraud Protection Service 14.0.1.1, 14.1.2.3, 15.1.0; F5 Big-Ip Global Traffic Manager 14.0.1.1, 14.1.2.3, 15.1.0; F5 Big-Ip Link Controller 14.0.1.1, 14.1.2.3, 15.1.0; F5 BIG-IP (LTM) 14.0.1.1, 14.1.2.3, 15.1.0; F5 Networks, Inc. BIG-IP (PEM) 14.0.1.1, 14.1.2.3, 15.1.0. Check the vendor advisory for mitigations.

References

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