8.6High

Cisco Adaptive Security Appliance Software

CVE-2018-0228

A vulnerability in the ingress flow creation functionality of Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause the CPU to increase upwards of 100% utilization, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to incorrect handling of an internal software lock that could prevent other system processes from getting CPU cycles, causing a high CPU condition. An attacker could exploit this vulnerability by sending a steady stream of malicious IP packets that can cause connections to be created on the targeted device. A successful exploit could allow the attacker to exhaust CPU resources, resulting in a DoS condition during which traffic through the device could be delayed. This vulnerability applies to either IPv4 or IPv6 ingress traffic. This vulnerability affects Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliances (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliances (ASAv), Firepower 2100 Series Security Appliances, Firepower 4110 Security Appliances, Firepower 9300 ASA Security Modules. Cisco Bug IDs: CSCvf63718.

What this means for your business

  • It affects Cisco Adaptive Security Appliance Software. It matters if your company, or a supplier that handles your data, runs it.
  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 4% chance of attack attempts being seen in the next 30 days, ranking above 88% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Cisco Adaptive Security Appliance Software, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
8.6 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Weakness
CWE-20
Assigned by
psirt@cisco.com

Dates

Published
2018-04-19
Last modified
2026-08-11
Sources
NVD

Affected products

  • Cisco Adaptive Security Appliance Software9.1 - 9.1.7.20, 9.3 - 9.4.4.13, 9.5 - 9.6.3.17, 9.7 - 9.7.1.16, 9.8 - 9.8.2.14, 9.2 - 9.2.4.27, 9.9 - 9.9.1, 98.1\(12.187\)
  • Cisco Secure Firewall Threat Defense6.0 - 6.1.0.6, 6.2.0 - 6.2.0.5, 6.2.1 - 6.2.2.2

As listed in the NVD configuration data. Not a statement about your estate.

References