VDB-210379 · CVE-2022-20837 · GCVE-0-2022-20837

Cisco IOS XE DNS ALG unusual condition

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.1	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Cisco IOS XE. This issue affects some unknown processing of the component DNS ALG. This manipulation causes unusual condition. The identification of this vulnerability is CVE-2022-20837. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Cisco IOS XE (Router Operating System) (affected version unknown) and classified as critical. Affected by this vulnerability is an unknown functionality of the component DNS ALG. The manipulation with an unknown input leads to a unusual condition vulnerability. The CWE definition for the vulnerability is CWE-754. The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product. As an impact it is known to affect availability. The summary by CVE is:

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.

The weakness was shared 10/11/2022 as cisco-sa-alg-dos-KU9Z8kFX. It is possible to read the advisory at tools.cisco.com. This vulnerability is known as CVE-2022-20837 since 11/02/2021. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/31/2022).

Upgrading eliminates this vulnerability.

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Productinfo

Type

Router Operating System

Vendor

Cisco

Name

IOS XE

License

commercial

Website

Vendor: https://www.cisco.com/

CPE 2.3info

🔍

CPE 2.2info

🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.2
VulDB Meta Temp Score: 8.1

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.6
NVD Vector: 🔍

CNA Base Score: 8.6
CNA Vector (Cisco Systems, Inc.): 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Unusual condition
CWE: CWE-754
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

11/02/2021 🔍
10/11/2022 +342 days 🔍
10/11/2022 +0 days 🔍
10/31/2022 +20 days 🔍

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-alg-dos-KU9Z8kFX
Status: Confirmed

CVE: CVE-2022-20837 (🔍)
GCVE (CVE): GCVE-0-2022-20837
GCVE (VulDB): GCVE-100-210379
scip Labs: https://www.scip.ch/en/?labs.20150108

Entryinfo

Created: 10/11/2022 09:46
Updated: 10/31/2022 14:37
Changes: 10/11/2022 09:46 (50), 10/31/2022 14:37 (11)
Complete: 🔍
Cache ID: 216::103