🛡️ CVE-2022-20837 — ios-xe

🟠 CVSS 8.6 — High ✅ No Known Exploit CWE-754 NVD
8.6
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality none, integrity none, availability high.

Weakness class

CVE-2022-20837 is classified as CWE-754: Improper Check for Unusual or Exceptional Conditions. 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.

Affected software

CVE-2022-20837 is recorded against 1 package.

  • ios-xe

Timeline and source

Published on 10 October 2022 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

tools.cisco.com
tools.cisco.com

Details

Severity HIGH
CVSS Score 8.6
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CWE CWE-754
Public Exploit ✅ No
Source NVD
Published 2022-10-10
Updated 2026-08-11
Modified 2026-06-17
Fix URL N/A

Affected Packages

Software From version Fixed in
ios-xe — —

Similar Threats

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