Multiple versions of Cisco ONS 15327, ONS 15454, and ONS 15454 SDH, including 4.6(0) and 4.6(1), 4.5(x), 4.1(0) to 4.1(3), 4.0(0) to 4.0(2), and earlier versions, and ONS 15600 1.x(x), allows remote attackers to cause a denial of service (control card reset) via malformed (1) TCP and (2) UDP packets.