Cisco voice products, when running the IBM Director Agent on IBM servers before OS 2000.2.6, allows remote attackers to cause a denial of service (CPU consumption) via arbitrary packets to TCP port 14247, as demonstrated using port scanning.
https://exchange.xforce.ibmcloud.com/vulnerabilities/14901
http://www.securitytracker.com/id?1008814
http://www.kb.cert.org/vuls/id/721092
http://www.cisco.com/warp/public/707/cisco-sa-20040121-voice.shtml