Cisco IOS 12.0 through 12.4 on Gigabit Switch Router (GSR) devices (aka 12000 Series routers) allows remote attackers to cause a denial of service (device crash) via a malformed Protocol Independent Multicast (PIM) packet.

Unspecified vulnerability in Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service (device reload) via a crafted Protocol Independent Multicast (PIM) packet.

The data-link switching (DLSw) component in Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service (device restart or memory consumption) via crafted (1) UDP port 2067 or (2) IP protocol 91 packets.

Stack-based buffer overflow in the Line Printer Daemon (LPD) in Cisco IOS before 12.2(18)SXF11, 12.4(16a), and 12.4(2)T6 allow remote attackers to execute arbitrary code by setting a long hostname on the target system, then causing an error message to be printed, as demonstrated by a telnet session to the LPD from a source port other than 515.

Cisco IOS 9.x, 10.x, 11.x, and 12.x and IOS XR 2.0.x, 3.0.x, and 3.2.x allows remote attackers to cause a denial of service or execute arbitrary code via a crafted IP option in the IP header in a (1) ICMP, (2) PIMv2, (3) PGM, or (4) URD packet.

Memory leak in the TCP listener in Cisco IOS 9.x, 10.x, 11.x, and 12.x allows remote attackers to cause a denial of service by sending crafted TCP traffic to an IPv4 address on the IOS device.

Cisco IOS allows remote attackers to cause a denial of service (crash) via a crafted IPv6 Type 0 Routing header.

Cisco IOS 12.0 through 12.4 and IOS XR before 3.2, with IPv6 enabled, allows remote attackers on a local network segment to cause a denial of service (device reload) and possibly execute arbitrary code via a crafted IPv6 packet.

Cisco IOS 12.2T through 12.4 allows remote attackers to bypass Authentication, Authorization, and Accounting (AAA) RADIUS authentication, if the fallback method is set to none, via a long username.

Secure Shell (SSH) 2 in Cisco IOS 12.0 through 12.3 allows remote attackers to cause a denial of service (device reload) (1) via a username that contains a domain name when using a TACACS+ server to authenticate, (2) when a new SSH session is in the login phase and a currently logged in user issues a send command, or (3) when IOS is logging messages and an SSH session is terminated while the server is sending data.