CVE-2025-20340: Cisco IOS XR Address Resolution Protocol Broadcast Storm Vulnerability

Published Sep 10, 2025
·
Updated

A vulnerability in the Address Resolution Protocol (ARP) implementation of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to trigger a broadcast storm, leading to a denial of service (DoS) condition on an affected device.  This vulnerability is due to how Cisco IOS XR Software processes a high, sustained rate of ARP traffic hitting the management interface. Under certain conditions, an attacker could exploit this vulnerability by sending an excessive amount of traffic to the management interface of an affected device, overwhelming its ARP processing capabilities. A successful exploit could result in degraded device performance, loss of management connectivity, and complete unresponsiveness of the system, leading to a DoS condition.

Affected Software

1 affected component
Cisco IOS XR Software

Event History

Sep 10, 2025
CVE Published
via MITRE·04:06 PM
Data Sourced
via MITRE·04:06 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·04:15 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2025-20340?

CVE-2025-20340 has a high severity level due to its potential to cause a denial of service (DoS) condition.

2

How do I fix CVE-2025-20340?

To fix CVE-2025-20340, upgrade to the latest version of Cisco IOS XR Software that addresses this vulnerability.

3

Who is affected by CVE-2025-20340?

CVE-2025-20340 affects devices running Cisco IOS XR Software that utilize the Address Resolution Protocol (ARP).

4

What can an attacker do with CVE-2025-20340?

An adjacent, unauthenticated attacker can trigger a broadcast storm using CVE-2025-20340, leading to a denial of service.

5

Is CVE-2025-20340 exploitable remotely?

No, CVE-2025-20340 is not remotely exploitable as it requires an adjacent attacker.

Contact

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