title: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Transparent Mode Denial of Service Vulnerability
description: A vulnerability in the TCP Normalizer of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software operating in transparent mode could allow an unauthenticated, remote attacker to poison MAC address tables, resulting in a denial of service (DoS) vulnerability. This vulnerability is due to incorrect handling of certain TCP segments when the affected device is operating in transparent mode. An attacker could exploit this vulnerability by sending a crafted TCP segment through an affected device. A successful exploit could allow the attacker to poison the MAC address tables in adjacent devices, resulting in network disruption.
problem types: CWE-924
affected:
{
product: Cisco Adaptive Security Appliance (ASA) Software
vendor: Cisco
versions:
status: affected, version: n/a
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 8.6
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
version: 3.1
]
exploits: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.