CVE-2010-4671: Cisco IOS

High severity, CVSS 7.8. EPSS: 3.6% chance of exploitation in the next 30 days.

The Neighbor Discovery (ND) protocol implementation in the IPv6 stack in Cisco IOS before 15.0(1)XA5 allows remote attackers to cause a denial of service (CPU consumption and device hang) by sending many Router Advertisement (RA) messages with different source addresses, as demonstrated by the flood_router6 program in the thc-ipv6 package, aka Bug ID CSCti33534.

Affected products

• Cisco IOS: before 15.0\(1\)xa5 (fixed in 15.0\(1\)xa5)

Published 2011-01-07. Last modified 2026-06-16.