CVE-2021-1377 Cisco IOS and IOS XE Software ARP Resource Management Exhaustion Denial of Service Vulnerability

Medium 5.8 Published 24 Mar 2021 Updated 8 Nov 2024

Remote attackers can cause denial of service by exhausting ARP resources, preventing legitimate host resolution on Cisco IOS devices.

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-2021-1377?

CVE-2021-1377 is a medium-severity denial of service vulnerability in Cisco Ios, published on 24 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in Address Resolution Protocol (ARP) management of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to prevent an affected device from resolving ARP entries for legitimate hosts on the connected subnets. This vulnerability exists because ARP entries are mismanaged. An attacker could exploit this vulnerability by continuously sending traffic that results in incomplete ARP entries. A successful exploit could allow the attacker to cause ARP requests on the device to be unsuccessful for legitimate hosts, resulting in a denial of service (DoS) condition.

Weakness: CWE-399

Which versions are affected by CVE-2021-1377?

It affects 2 products.

Products include Cisco Ios, Cisco Ios Xe.

How do I fix CVE-2021-1377?

No fix has been published for CVE-2021-1377 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-2021-1377 being exploited?

There is no known exploitation of CVE-2021-1377 in the wild and no public exploit code.

All Cisco Ios vulnerabilities

Sources

Also known as GHSA-cw7w-jj3r-j3jw.