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 4.6(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 4.1(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.

Cisco Internetwork Operating System (IOS) 12.0S through 12.3T attempts to process SNMP solicited operations on improper ports (UDP 162 and a randomly chosen UDP port), which allows remote attackers to cause a denial of service (device reload and memory corruption).

Cisco IOS 11.x and 12.0 through 12.2 allows remote attackers to cause a denial of service (traffic block) by sending a particular sequence of IPv4 packets to an interface on the device, causing the input queue on that interface to be marked as full.

Cisco ONS15454 and ONS15327 running ONS before 3.4 have an account for the VxWorks Operating System in the TCC, TCC+ and XTC that cannot be changed or disabled, which allows remote attackers to gain privileges by connecting to the account via Telnet.

Cisco ONS15454 and ONS15327 running ONS before 3.4 stores usernames and passwords in cleartext in the image database for the TCC, TCC+ or XTC, which could allow attackers to gain privileges by obtaining the passwords from the image database or a backup.

Cisco ONS15454 and ONS15327 running ONS before 3.4 allows remote attackers to modify the system configuration and delete files by establishing an FTP connection to the TCC, TCC+ or XTC using a username and password that does not exist.