A vulnerability in the Precision Time Protocol (PTP) subsystem of Cisco IOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition of the Precision Time Protocol. The vulnerability is due to insufficient processing of PTP packets. An attacker could exploit this vulnerability by sending a custom PTP packet to, or through, an affected device. A successful exploit could allow the attacker to cause a DoS condition for the PTP subsystem, resulting in time synchronization issues across the network.