Cisco IOS XR 4.3.4 through 5.3.0 on ASR 9000 devices when uRPF PBR QoS or an ACL is configured does not properly handle bridge-group virtual interface (BVI) traffic which allows remote attackers to cause a denial of service (chip and card hangs and reloads) by triggering use of a BVI interface for IPv4 packets aka Bug ID CSCur62957.