CVE-2018-15443

Name: CVE-2018-15443
Creator: NVD / NIST
Published: 2018-11-08T17:29:00.653+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 2.77%

Last modified Jun 17, 2026

CVE-2018-15443 is a vulnerability of currently unknown severity. 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. EPSS estimates a 2.77% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability

2.77%

84.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Firepower System Software	All versions

References

http://www.securityfocus.com/bid/105870Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181107-fde-tcp-bypassVendor Advisory
http://www.securityfocus.com/bid/105870Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181107-fde-tcp-bypassVendor Advisory

Timeline

Published: Nov 8, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-15443?

How severe is CVE-2018-15443?

Severity scoring for CVE-2018-15443 is pending analysis. The EPSS model estimates a 2.77% probability of exploitation in the next 30 days.

How do I fix CVE-2018-15443?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-15443?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST