Control cards for Cisco Optical Networking System (ONS) 15000 series nodes before 20060405 allow remote attackers to cause a denial of service (card reset) via (1) a \crafted\ IP packet to a device with secure mode EMS-to-network-element access aka bug ID CSCsc51390; (2) a \crafted\ IP packet to a device with IP on the LAN interface aka bug ID CSCsd04168; and (3) a \malformed\ OSPF packet aka bug ID CSCsc54558.