CVE-2022-20837 HIGH

CVE-2022-20837: Cisco IOS XE Software DNS NAT Protocol Application Layer Gateway Denial of Service Vulnerability

Vendor Cisco
Product Cisco IOS XE Software
Weakness CWE-754
Published October 10, 2022
Last update November 1, 2024

CVSS base score

8.6/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

A vulnerability in the DNS application layer gateway (ALG) functionality that is used by Network Address Translation (NAT) in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. This vulnerability is due to a logic error that occurs when an affected device inspects certain TCP DNS packets. An attacker could exploit this vulnerability by sending crafted DNS packets through the affected device that is performing NAT for DNS packets. A successful exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition on the affected device. Note: This vulnerability can be exploited only by sending IPv4 TCP packets through an affected device. This vulnerability cannot be exploited by sending IPv6 traffic.

Key dates

02Disclosure timeline

October 10, 2022 CVE published
November 1, 2024 Record updated