---
id: CVE-2018-0230
title: >-
  A vulnerability in the internal packet-processing functionality of Cisco
  Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series
  Security Appliances could allow an unauthenticated, remote attacker to cause
  an affected dev…
summary: >-
  A vulnerability in the internal packet-processing functionality of Cisco
  Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series
  Security Appliances could allow an unauthenticated, remote attacker to cause
  an affected dev…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'
cwe:
  - CWE-400
  - CWE-400
vendor: cisco
product: secure_firewall_threat_defense
affected:
  - secure_firewall_threat_defense = 6.2.1
  - secure_firewall_threat_defense = 6.2.2
  - adaptive_security_appliance_software = 9.8(2)
published: '2018-04-19'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2018-0230'
references:
  - url: 'http://www.securityfocus.com/bid/103931'
    label: psirt@cisco.com
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-fp2100
    label: psirt@cisco.com
  - url: 'http://www.securityfocus.com/bid/103931'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-fp2100
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.02397
epssPercentile: 0.83277
ingestedAt: '2026-08-11T19:48:25.541Z'
---

## Overview

A vulnerability in the internal packet-processing functionality of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Security Appliances could allow an unauthenticated, remote attacker to cause an affected device to stop processing traffic, resulting in a denial of service (DoS) condition. The vulnerability is due to the affected software improperly validating IP Version 4 (IPv4) and IP Version 6 (IPv6) packets after the software reassembles the packets (following IP Fragmentation). An attacker could exploit this vulnerability by sending a series of malicious, fragmented IPv4 or IPv6 packets to an affected device. A successful exploit could allow the attacker to cause Snort processes on the affected device to hang at 100% CPU utilization, which could cause the device to stop processing traffic and result in a DoS condition until the device is reloaded manually. This vulnerability affects Cisco Firepower Threat Defense (FTD) Software Releases 6.2.1 and 6.2.2, if the software is running on a Cisco Firepower 2100 Series Security Appliance. Cisco Bug IDs: CSCvf91098.

## Affected

- `secure_firewall_threat_defense = 6.2.1`
- `secure_firewall_threat_defense = 6.2.2`
- `adaptive_security_appliance_software = 9.8(2)`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.