The Local Packet Transport Services (LPTS) implementation in Cisco IOS XR 5.1.2, 5.1.3, 5.2.1, and 5.2.2 on ASR9k devices makes incorrect decisions about the opening of TCP and UDP ports during the processing of flow base entries, which allows remote attackers to cause a denial of service (resource consumption) by sending traffic to these ports continuously, aka Bug ID CSCur88273.