CVE-2025-20340
Cisco IOS XR Address Resolution Protocol Broadcast Storm Vulnerability
Description
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.
INFO
Published Date :
Sept. 10, 2025, 4:15 p.m.
Last Modified :
Sept. 26, 2026, 12:10 a.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Apply Cisco IOS XR Software security patches.
- Configure access control lists for management interface.
- Limit ARP traffic rates to the device.
- Monitor network traffic for anomalies.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-20340.
| URL | Resource |
|---|---|
| https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-arp-storm-EjUU55yM |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-20340 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-20340
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-20340 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-20340 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Sep. 26, 2026
Action Type Old Value New Value Added Translation Title: el archivo menu/pop.html en el parámetro myurl en la interfaz de administración en Alcatel-Lucent 1830 Photonic Service Switch (PSS), Description: Una vulnerabilidad en la implementación del Protocolo de Resolución de Direcciones (ARP) de Cisco IOS XR Software podría permitir a un atacante no autenticado y adyacente desencadenar una tormenta de difusión, lo que llevaría a una condición de denegación de servicio (DoS) en un dispositivo afectado. Esta vulnerabilidad se debe a cómo Cisco IOS XR Software procesa una tasa alta y sostenida de tráfico ARP que llega a la interfaz de gestión. Bajo ciertas condiciones, un atacante podría explotar esta vulnerabilidad enviando una cantidad excesiva de tráfico a la interfaz de gestión de un dispositivo afectado, sobrecargando sus capacidades de procesamiento ARP. Un exploit exitoso podría resultar en un rendimiento degradado del dispositivo, pérdida de conectividad de gestión y una falta total de respuesta del sistema, lo que llevaría a una condición de DoS. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Cisco', 'product': 'Cisco IOS XR Software', 'versions': [{'status': 'affected', 'version': '6.5.3'}, {'status': 'affected', 'version': '6.5.29'}, {'status': 'affected', 'version': '6.5.1'}, {'status': 'affected', 'version': '6.6.1'}, {'status': 'affected', 'version': '6.5.2'}, {'status': 'affected', 'version': '6.5.92'}, {'status': 'affected', 'version': '6.5.15'}, {'status': 'affected', 'version': '6.6.2'}, {'status': 'affected', 'version': '7.0.1'}, {'status': 'affected', 'version': '6.6.25'}, {'status': 'affected', 'version': '6.5.26'}, {'status': 'affected', 'version': '6.6.11'}, {'status': 'affected', 'version': '6.5.25'}, {'status': 'affected', 'version': '6.5.28'}, {'status': 'affected', 'version': '6.5.93'}, {'status': 'affected', 'version': '6.6.12'}, {'status': 'affected', 'version': '6.5.90'}, {'status': 'affected', 'version': '7.0.0'}, {'status': 'affected', 'version': '7.1.1'}, {'status': 'affected', 'version': '7.0.90'}, {'status': 'affected', 'version': '6.6.3'}, {'status': 'affected', 'version': '6.7.1'}, {'status': 'affected', 'version': '7.0.2'}, {'status': 'affected', 'version': '7.1.15'}, {'status': 'affected', 'version': '7.2.0'}, {'status': 'affected', 'version': '7.2.1'}, {'status': 'affected', 'version': '7.1.2'}, {'status': 'affected', 'version': '6.7.2'}, {'status': 'affected', 'version': '7.0.11'}, {'status': 'affected', 'version': '7.0.12'}, {'status': 'affected', 'version': '7.0.14'}, {'status': 'affected', 'version': '7.1.25'}, {'status': 'affected', 'version': '6.6.4'}, {'status': 'affected', 'version': '7.2.12'}, {'status': 'affected', 'version': '7.3.1'}, {'status': 'affected', 'version': '7.1.3'}, {'status': 'affected', 'version': '6.7.3'}, {'status': 'affected', 'version': '7.4.1'}, {'status': 'affected', 'version': '7.2.2'}, {'status': 'affected', 'version': '6.7.4'}, {'status': 'affected', 'version': '6.5.31'}, {'status': 'affected', 'version': '7.3.15'}, {'status': 'affected', 'version': '7.3.16'}, {'status': 'affected', 'version': '6.8.1'}, {'status': 'affected', 'version': '7.4.15'}, {'status': 'affected', 'version': '6.5.32'}, {'status': 'affected', 'version': '7.3.2'}, {'status': 'affected', 'version': '7.5.1'}, {'status': 'affected', 'version': '7.4.16'}, {'status': 'affected', 'version': '7.3.27'}, {'status': 'affected', 'version': '7.6.1'}, {'status': 'affected', 'version': '7.5.2'}, {'status': 'affected', 'version': '7.8.1'}, {'status': 'affected', 'version': '7.6.15'}, {'status': 'affected', 'version': '7.5.12'}, {'status': 'affected', 'version': '7.8.12'}, {'status': 'affected', 'version': '7.3.3'}, {'status': 'affected', 'version': '7.7.1'}, {'status': 'affected', 'version': '6.8.2'}, {'status': 'affected', 'version': '7.3.4'}, {'status': 'affected', 'version': '7.4.2'}, {'status': 'affected', 'version': '6.7.35'}, {'status': 'affected', 'version': '6.9.1'}, {'status': 'affected', 'version': '7.6.2'}, {'status': 'affected', 'version': '7.5.3'}, {'status': 'affected', 'version': '7.7.2'}, {'status': 'affected', 'version': '6.9.2'}, {'status': 'affected', 'version': '7.9.1'}, {'status': 'affected', 'version': '7.10.1'}, {'status': 'affected', 'version': '7.8.2'}, {'status': 'affected', 'version': '7.5.4'}, {'status': 'affected', 'version': '6.5.33'}, {'status': 'affected', 'version': '7.8.22'}, {'status': 'affected', 'version': '7.7.21'}, {'status': 'affected', 'version': '7.9.2'}, {'status': 'affected', 'version': '7.3.5'}, {'status': 'affected', 'version': '7.5.5'}, {'status': 'affected', 'version': '7.11.1'}, {'status': 'affected', 'version': '7.9.21'}, {'status': 'affected', 'version': '7.10.2'}, {'status': 'affected', 'version': '24.1.1'}, {'status': 'affected', 'version': '7.6.3'}, {'status': 'affected', 'version': '7.3.6'}, {'status': 'affected', 'version': '7.5.52'}, {'status': 'affected', 'version': '7.11.2'}, {'status': 'affected', 'version': '24.2.1'}, {'status': 'affected', 'version': '24.1.2'}, {'status': 'affected', 'version': '24.2.11'}, {'status': 'affected', 'version': '24.3.1'}, {'status': 'affected', 'version': '24.4.1'}, {'status': 'affected', 'version': '24.2.2'}, {'status': 'affected', 'version': '7.8.23'}, {'status': 'affected', 'version': '7.11.21'}, {'status': 'affected', 'version': '24.2.20'}, {'status': 'affected', 'version': '24.3.2'}, {'status': 'affected', 'version': '24.4.10'}, {'status': 'affected', 'version': '6.5.35'}, {'status': 'affected', 'version': '25.1.1'}, {'status': 'affected', 'version': '24.4.2'}, {'status': 'affected', 'version': '24.3.20'}, {'status': 'affected', 'version': '24.4.15'}, {'status': 'affected', 'version': '6.5.351'}, {'status': 'affected', 'version': '24.3.30'}, {'status': 'affected', 'version': '6.5.352'}, {'status': 'affected', 'version': '24.4.30'}], 'defaultStatus': 'unknown'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2025-20340', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2025-09-10T18:30:55.478853Z'} -
New CVE Received by [email protected]
Sep. 10, 2025
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Added CWE CWE-400 Added Reference https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-arp-storm-EjUU55yM