CVE-2022-20920 Cisco IOS and IOS XE Software SSH Denial of Service Vulnerability

High 7.7 Published 10 Oct 2022 Updated 27 May 2026

An authenticated remote attacker can cause a Cisco IOS device to reload by sending specific SSH requests, resulting in a denial of service.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2022-20920?

CVE-2022-20920 is a high-severity denial of service vulnerability in Cisco Ios, published on 10 Oct 2022. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A vulnerability in the SSH implementation of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload. This vulnerability is due to improper handling of resources during an exceptional situation. An attacker could exploit this vulnerability by continuously connecting to an affected device and sending specific SSH requests. A successful exploit could allow the attacker to cause the affected device to reload.

Weakness: CWE-755

Which versions are affected by CVE-2022-20920?

It affects 2 products.

Products include Cisco Ios, Cisco Ios Xe.

How do I fix CVE-2022-20920?

No fix has been published for CVE-2022-20920 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2022-20920 being exploited?

There is no known exploitation of CVE-2022-20920 in the wild and no public exploit code.

All Cisco Ios vulnerabilities

Sources

Also known as GHSA-x4hg-95c5-c2vp.