CVE-2022-20837

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

Severity Score

8.6

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

Una vulnerabilidad en la funcionalidad de la puerta de enlace de la capa de aplicación (ALG) del DNS que usa Network Address Translation (NAT) en el software Cisco IOS XE podría permitir a un atacante remoto no autenticado causar la recarga de un dispositivo afectado. Esta vulnerabilidad es debido a un error lógico que es producido cuando un dispositivo afectado inspecciona determinados paquetes TCP DNS. Un atacante podría explotar esta vulnerabilidad mediante el envío de paquetes DNS diseñados mediante el dispositivo afectado que está llevando a cabo la NAT para los paquetes DNS. Una explotación con éxito podría permitir al atacante causar la recarga del dispositivo, resultando en una condición de negación de servicio (DoS) en el dispositivo afectado. Nota: Esta vulnerabilidad sólo puede ser explotada mediante el envío de paquetes TCP IPv4 mediante un dispositivo afectado. Esta vulnerabilidad no puede ser explotada mediante el envío de tráfico IPv6

*Credits: N/A

CVSS Scores

NISTv3.1 8.6

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-11-02 CVE Reserved
2022-10-10 CVE Published
2024-04-20 EPSS Updated
2024-09-16 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-754: Improper Check for Unusual or Exceptional Conditions

CAPEC

References (1)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-alg-dos-KU9Z8kFX	2023-11-07

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	-	-	Affected	in	Cisco Search vendor "Cisco"	Asr 1000-esp100-x Search vendor "Cisco" for product "Asr 1000-esp100-x"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	-	-	Affected	in	Cisco Search vendor "Cisco"	Asr 1000-esp200-x Search vendor "Cisco" for product "Asr 1000-esp200-x"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	-	-	Affected	in	Cisco Search vendor "Cisco"	Catalyst 8500 Search vendor "Cisco" for product "Catalyst 8500"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	-	-	Affected	in	Cisco Search vendor "Cisco"	Catalyst 8500-4qc Search vendor "Cisco" for product "Catalyst 8500-4qc"	-	-	Safe