A vulnerability in the Vector Packet Processor (VPP) of Cisco Packet Data Network Gateway (PGW) could allow an unauthenticated, remote attacker to stop ICMP traffic from being processed over an IPsec connection. This vulnerability is due to the VPP improperly handling a malformed packet. An attacker could exploit this vulnerability by sending a malformed Encapsulating Security Payload (ESP) packet over an IPsec connection. A successful exploit could allow the attacker to stop ICMP traffic over an IPsec connection and cause a denial of service (DoS).