The DHCP implementation in the PowerOn Auto Provisioning (POAP) feature in Cisco NX-OS does not properly restrict the initialization process, which allows remote attackers to execute arbitrary commands as root by sending crafted response packets on the local network, aka Bug ID CSCur14589.
http://www.securitytracker.com/id/1031992
http://tools.cisco.com/security/center/viewAlert.x?alertId=38062