CVE-2020-3500 Cisco StarOS IPv6 Denial of Service Vulnerability

Medium 6.8 Published 17 Aug 2020 Updated 13 Nov 2024

Unauthenticated remote attackers can cause a denial of service on Cisco StarOS devices by sending crafted IPv6 packets, requiring vendor patches.

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-2020-3500?

CVE-2020-3500 is a medium-severity denial of service vulnerability in Cisco ASR 5000 Series Software, published on 17 Aug 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the IPv6 implementation of Cisco StarOS could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of incoming IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet to an affected device with the goal of reaching the vulnerable section of the input buffer. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is specific to IPv6 traffic. IPv4 traffic is not affected.

Weakness: CWE-119

Which versions are affected by CVE-2020-3500?

It affects 1 product.

Products include Cisco Staros.

How do I fix CVE-2020-3500?

No fix has been published for CVE-2020-3500 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-2020-3500 being exploited?

There is no known exploitation of CVE-2020-3500 in the wild and no public exploit code.

Sources

Also known as GHSA-5vvg-4mgq-x55f.