What’s Vulnerable › Vulnerabilities

CVE-2018-15443: Cisco Firepower Detection Engine TCP Intrusion Prevention System Rule Bypass Vulnerability

• Severity: high (CVSS 7.5 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-11-08 · updated 2026-06-17
• Weakness: CWE-400

Description

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 FireSIGHT System Software: all versions

References

• http://www.securityfocus.com/bid/105870
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181107-fde-tcp-bypass
• http://www.securityfocus.com/bid/105870
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181107-fde-tcp-bypass

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