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CVE-2025-20146

Cisco IOS XR Software for ASR 9000 Series Routers Layer 3 Multicast Routing Denial of Service Vulnerability

Published: Mar 12, 2025Updated: Aug 1, 2025 Sources: CVE List NVD BDUCWE-20
NVD MITRE
8.6CVSSHIGH
EPSS Score
0.5%
Top 61.3%
CISA KEV
Not in KEV
Exploits
0 Known
Remediation
Patch Available

Description

A vulnerability in the Layer 3 multicast feature of Cisco IOS XR Software for Cisco ASR 9000 Series Aggregation Services Routers, ASR 9902 Compact High-Performance Routers, and ASR 9903 Compact High-Performance Routers could allow an unauthenticated, remote attacker to cause a line card to reset, resulting in a denial of service (DoS) condition. This vulnerability is due to the incorrect handling of malformed IPv4 multicast packets that are received on line cards where the interface has either an IPv4 access control list (ACL) or a QoS policy applied. An attacker could exploit this vulnerability by sending crafted IPv4 multicast packets through an affected device. A successful exploit could allow the attacker to cause line card exceptions or a hard reset. Traffic over that line card would be lost while the line card reloads.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:CC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-20NVD-CWE-noinfo

Affected Products

Cisco IOS XR SoftwareCisco
On-premNetwork Device
Networking Infrastructure / router-switch
ios xrcisco
EmbeddedNetwork Device
Networking Infrastructure / router-switch
Cisco IOS XRCisco Systems Inc.
On-premNetwork Device
Networking Infrastructure / router-switch
ciscocommercialUSNetworking Infrastructureaka cisco systems, cisco systems inc.
cisco systems inc.commercialUSNetworking Infrastructureaka cisco systems, cisco

Attack Graph

Products CVE Techniques Tactics

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Exploitability

0 exploit sources identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

MITRE ATT&CK

1 technique
Initial Access
View detailed technique mapping

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-multicast-ERMrSvq7
sec.cloudapps.cisco.com
https://blog.apnic.net/2024/09/02/crafting-endless-as-paths-in-bgp/
blog.apnic.net

Timeline

Published
Mar 12, 2025
Last Updated
Aug 1, 2025

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