Cisco IOS 12.1, 12.2, 12.3, and 12.4, with IPv4 UDP services and the IPv6 protocol enabled, allows remote attackers to cause a denial of service (device crash and possible blocked interface) via a crafted IPv6 packet to the device.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.032
EPSS Ranking 86.4%