CVE-2018-0228: A vulnerability in the ingress flow creation functionality of Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker ...

Description

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.

Metrics

CVSS 3.1

8.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS Probability

3.61%

88.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Adaptive Security Appliance Software	>= 9.1, < 9.1.7.20
Cisco	Adaptive Security Appliance Software	>= 9.3, < 9.4.4.13
Cisco	Adaptive Security Appliance Software	>= 9.5, < 9.6.3.17
Cisco	Adaptive Security Appliance Software	>= 9.7, < 9.7.1.16
Cisco	Adaptive Security Appliance Software	>= 9.8, < 9.8.2.14
Cisco	Adaptive Security Appliance Software	>= 9.2, < 9.2.4.27
Cisco	Adaptive Security Appliance Software	>= 9.9, < 9.9.1
Cisco	Adaptive Security Appliance Software	98.1\(12.187\)
Cisco	Firepower Threat Defense	>= 6.0, < 6.1.0.6
Cisco	Firepower Threat Defense	>= 6.2.0, < 6.2.0.5
Cisco	Firepower Threat Defense	>= 6.2.1, < 6.2.2.2

References

http://www.securityfocus.com/bid/104220Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040724Third Party Advisory, VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-18-184-01Third Party Advisory, US Government Resource
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-asa2Mitigation, Vendor Advisory
http://www.securityfocus.com/bid/104220Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040724Third Party Advisory, VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-18-184-01Third Party Advisory, US Government Resource
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-asa2Mitigation, Vendor Advisory

Timeline

Published: Apr 19, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is 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.

How severe is CVE-2018-0228?

CVE-2018-0228 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 3.61% probability of exploitation in the next 30 days.

How do I fix CVE-2018-0228?

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.