CVE-2021-34697 Cisco IOS XE Software Protection Against Distributed Denial of Service Attacks Feature Vulnerability

Medium 5.8 Published 23 Sep 2021 Updated 7 Nov 2024

Remote attackers can cause denial of service on Cisco IOS XE devices if specific anti-DoS features are configured incorrectly.

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

What is CVE-2021-34697?

CVE-2021-34697 is a medium-severity denial of service vulnerability in Cisco Ios Xe, published on 23 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the Protection Against Distributed Denial of Service Attacks feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct denial of service (DoS) attacks to or through the affected device. This vulnerability is due to incorrect programming of the half-opened connections limit, TCP SYN flood limit, or TCP SYN cookie features when the features are configured in vulnerable releases of Cisco IOS XE Software. An attacker could exploit this vulnerability by attempting to flood traffic to or through the affected device. A successful exploit could allow the attacker to initiate a DoS attack to or through an affected device.

Weakness: CWE-665

Which versions are affected by CVE-2021-34697?

It affects 1 product.

Products include Cisco Ios Xe.

How do I fix CVE-2021-34697?

No fix has been published for CVE-2021-34697 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-2021-34697 being exploited?

There is no known exploitation of CVE-2021-34697 in the wild and no public exploit code.

All Cisco Ios Xe vulnerabilities

Sources

Also known as GHSA-7jmp-v8mh-4f8r.