CVE-2020-27716: 
F5 BIG-IP Virtual Edition vulnerability analysis and mitigation

CVE-2020-27716 is a high-severity vulnerability affecting F5 Networks' BIG-IP Access Policy Manager (APM). The vulnerability was discovered and disclosed in December 2020, affecting multiple versions of the BIG-IP system including 15.1.0-15.1.0.5, 14.1.0-14.1.3, 13.1.0-13.1.3.5, 12.1.0-12.1.5.2, and 11.6.1-11.6.5.2 (NVD).

The vulnerability is related to the Traffic Management Microkernel (TMM) component, which processes all load-balanced traffic on BIG-IP systems. When a BIG-IP APM virtual server processes specific types of traffic, the TMM stops responding and restarts. The vulnerability has received a CVSS v3.1 base score of 7.5 (High) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (NVD).

When exploited, the vulnerability causes the Traffic Management Microkernel (TMM) to stop responding and restart, leading to service disruption. If the affected BIG-IP system is configured as part of a device group, the system triggers a failover to the peer device. This results in temporary interruption of traffic processing while TMM restarts (SecurityWeek).

The vulnerability can be exploited remotely without requiring special tools. An attacker can trigger the vulnerability by sending specially crafted HTTP requests to the server hosting the BIG-IP configuration utility, resulting in a denial-of-service condition (SecurityWeek).

F5 Networks has released security updates to address this vulnerability in both 14.x and 15.x branches. Organizations running affected versions should upgrade to the patched versions to mitigate the risk (SecurityWeek).