An unauthenticated remote attacker may be able to disrupt services on F5 BIG-IP 11.4.1 - 11.5.4 devices with maliciously crafted network traffic. This vulnerability affects virtual servers associated with TCP profiles when the BIG-IP system's tm.tcpprogressive db variable value is set to non-default setting "enabled". The default value for the tm.tcpprogressive db variable is "negotiate". An attacker may be able to disrupt traffic or cause the BIG-IP system to fail over to another device in the device group.