Cisco Adaptive Security Appliance Flow Creation Denial of Service Vulnerability

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 percent 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 either to or across an affected device.

Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability.

This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-asa2 [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-asa2”]