CVE-2023-20233 Denial of service in Cisco IOS XR Software

Medium 4.3 Published 13 Sep 2023 Updated 2 Aug 2024

Unauthenticated remote attackers can crash the CFM service by sending crafted continuity check messages, requiring CFM to be enabled.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2023-20233?

CVE-2023-20233 is a medium-severity denial of service vulnerability in Cisco Ios Xr, published on 13 Sep 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

A vulnerability in the Connectivity Fault Management (CFM) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incorrect processing of invalid continuity check messages (CCMs). An attacker could exploit this vulnerability by sending crafted CCMs to an affected device. A successful exploit could allow the attacker to cause the CFM service to crash when a user displays information about maintenance end points (MEPs) for peer MEPs on an affected device.

Weakness: CWE-354, CWE-476

Which versions are affected by CVE-2023-20233?

It affects 1 product.

Products include Cisco Ios Xr.

How do I fix CVE-2023-20233?

No fix has been published for CVE-2023-20233 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-2023-20233 being exploited?

There is no known exploitation of CVE-2023-20233 in the wild and no public exploit code.

All Cisco Ios Xr vulnerabilities

Sources

Also known as GHSA-346q-rm44-2j2v.