CVE-2018-15443: Cisco Firepower System Software

High severity, CVSS 7.5. EPSS: 2.8% chance of exploitation in the next 30 days.

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.

Affected products

• Cisco Firepower System Software: affected versions not specified

Published 2018-11-08. Last modified 2026-06-17.