cisco-sa-20181107-fde-tcp-bypass

Cisco Firepower Detection Engine TCP Intrusion Prevention System Rule Bypass Vulnerability

A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a configured Intrusion Prevention System (IPS) rule that inspects certain types of TCP traffic. The vulnerability is due to incorrect TCP retransmission handling. An attacker could exploit this vulnerability by sending a crafted TCP connection request through an affected device. A successful exploit could allow the attacker to bypass configured IPS rules and allow uninspected traffic onto the network. There are no workarounds that address this vulnerability.