A vulnerability in the Local Packet Transport Services (LPTS) feature set of Cisco ASR 9000 Series Aggregation Services Router Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a lack of input and validation checking on certain Precision Time Protocol (PTP) ingress traffic to an affected device. An attacker could exploit this vulnerability by injecting malformed traffic into an affected device. A successful exploit could allow the attacker to cause services on the device to become unresponsive, resulting in a DoS condition. Cisco Bug IDs: CSCvj22858.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180815-asr-ptp-dos