CVE-2023-20187 Denial of service in Cisco IOS XE Software

High 8.6 Published 27 Sep 2023 Updated 2 Aug 2024

Unauthenticated remote attackers can cause a denial of service on Cisco ASR 1000 routers by sending specific IPv6 multicast packets when mLRE is enabled.

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-2023-20187?

CVE-2023-20187 is a high-severity denial of service vulnerability in Cisco Ios Xe, published on 27 Sep 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the Multicast Leaf Recycle Elimination (mLRE) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to incorrect handling of certain IPv6 multicast packets when they are fanned out more than seven times on an affected device. An attacker could exploit this vulnerability by sending a specific IPv6 multicast or IPv6 multicast VPN (MVPNv6) packet through the affected device. A successful exploit could allow the attacker to cause a reload of the affected device, resulting in a DoS condition.

Weakness: CWE-823

Which versions are affected by CVE-2023-20187?

It affects 1 product.

Products include Cisco Ios Xe.

How do I fix CVE-2023-20187?

No fix has been published for CVE-2023-20187 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-2023-20187 being exploited?

There is no known exploitation of CVE-2023-20187 in the wild and no public exploit code.

All Cisco Ios Xe vulnerabilities

Sources

Also known as GHSA-w9wf-g769-rjv3.