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, allows remote attackers to cause a denial of service (control card reset) via malformed (1) IP or (2) ICMP packets.

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.

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

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, allows remote attackers to cause a denial of service (control card reset) via a large number of TCP connections with an invalid response instead of the final ACK (TCP-ACK).

The Transaction Language 1 (TL1) login interface in Cisco ONS 15327 4.6(0) and 4.6(1) and 15454 and 15454 SDH 4.6(0) and 4.6(1), when a user account is configured with a blank password, allows remote attackers to gain unauthorized access by logging in with a password larger than 10 characters.