CVE-2018-0240: Multiple vulnerabilities in the Application Layer Protocol Inspection feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower ...

Description

Multiple vulnerabilities in the Application Layer Protocol Inspection feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerabilities are due to logical errors during traffic inspection. An attacker could exploit these vulnerabilities by sending a high volume of malicious traffic across an affected device. An exploit could allow the attacker to cause a deadlock condition, resulting in a reload of an affected device. These vulnerabilities affect Cisco ASA Software and Cisco FTD Software configured for Application Layer Protocol Inspection running on the following Cisco products: 3000 Series Industrial Security Appliance (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 Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4100 Series Security Appliance, Firepower 9300 ASA Security Module, FTD Virtual (FTDv). Cisco Bug IDs: CSCve61540, CSCvh23085, CSCvh95456.

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

3.86%

88.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-399

Affected Software

Vendor	Product	Versions
Cisco	Firepower Threat Defense	>= 6.1.0, <= 6.1.0.7
Cisco	Firepower Threat Defense	>= 6.2.0, < 6.2.0.5
Cisco	Firepower Threat Defense	>= 6.2.1, < 6.2.2.2
Cisco	Adaptive Security Appliance Software	>= 9.6.0.0, < 9.6.4.6
Cisco	Adaptive Security Appliance Software	>= 9.7.0.0, < 9.7.1.24
Cisco	Adaptive Security Appliance Software	>= 9.8.0.0, < 9.8.2.24
Cisco	Adaptive Security Appliance Software	>= 9.9.0.0, < 9.9.1.4

References

http://www.securityfocus.com/bid/103934Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040722Broken Link, Third 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-asa_inspectVendor Advisory
http://www.securityfocus.com/bid/103934Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040722Broken Link, Third 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-asa_inspectVendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2018-0240?

Multiple vulnerabilities in the Application Layer Protocol Inspection feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerabilities are due to logical errors during traffic inspection. An attacker could exploit these vulnerabilities by sending a high volume of malicious traffic across an affected device. An exploit could allow the attacker to cause a deadlock condition, resulting in a reload of an affected device. These vulnerabilities affect Cisco ASA Software and Cisco FTD Software configured for Application Layer Protocol Inspection running on the following Cisco products: 3000 Series Industrial Security Appliance (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 Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4100 Series Security Appliance, Firepower 9300 ASA Security Module, FTD Virtual (FTDv). Cisco Bug IDs: CSCve61540, CSCvh23085, CSCvh95456.

How severe is CVE-2018-0240?

CVE-2018-0240 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 3.86% probability of exploitation in the next 30 days.

How do I fix CVE-2018-0240?

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.