CVE-2022-20837

Cisco IOS XE Software DNS NAT Protocol Application Layer Gateway Denial of Service Vulnerability

State: Published
Severity: 8.6 High
Published: Oct 10, 2022
Updated: Nov 1, 2024
Reserved: Nov 2, 2021

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	8.6 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H	cisco

Weaknesses

CWE-754

Affected Products

Product	Versions
Cisco IOS XE SoftwareCisco	n/aAffected

References

20220928 Cisco IOS XE Software DNS NAT Protocol Application Layer Gateway Denial of Service Vulnerabilityvendor-advisory

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