Vulnerability 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 Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Ios Xr | 7.9.21 |
| Cisco | Asr 9006 | - |
| Cisco | Asr 9010 | - |
| Cisco | Asr 9901 | - |
| Cisco | Asr 9902 | - |
| Cisco | Asr 9903 | - |
| Cisco | Asr 9904 | - |
| Cisco | Asr 9906 | - |
| Cisco | Asr 9910 | - |
| Cisco | Asr 9912 | - |
| Cisco | Asr 9922 | - |
Related Weaknesses (CWE)
References
- https://blog.apnic.net/2024/09/02/crafting-endless-as-paths-in-bgp/Not Applicable
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/ciVendor Advisory
FAQ
What is CVE-2025-20146?
CVE-2025-20146 is a vulnerability with a CVSS score of 8.6 (HIGH). 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-P...
How severe is CVE-2025-20146?
CVE-2025-20146 has been rated HIGH with a CVSS base score of 8.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-20146?
Check the references section above for vendor advisories and patch information. Affected products include: Cisco Ios Xr, Cisco Asr 9006, Cisco Asr 9010, Cisco Asr 9901, Cisco Asr 9902.