Cisco IOS 12.1, 12.2, 12.3, and 12.4, with IPv4 UDP services and the IPv6 protocol enabled, allows remote attackers to cause a denial of service (device crash and possible blocked interface) via a crafted IPv6 packet to the device.

Unspecified vulnerability in the Extensible Authentication Protocol (EAP) implementation in Cisco IOS 12.3 and 12.4 on Cisco Access Points and 1310 Wireless Bridges (Wireless EAP devices), IOS 12.1 and 12.2 on Cisco switches (Wired EAP devices), and CatOS 6.x through 8.x on Cisco switches allows remote attackers to cause a denial of service (device reload) via a crafted EAP Response Identity packet.

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.

Unspecified vulnerability in Cisco IOS 12.0 through 12.4 allows context-dependent attackers to cause a denial of service (device restart and BGP routing table rebuild) via certain regular expressions in a "show ip bgp regexp" command. NOTE: unauthenticated remote attacks are possible in environments with anonymous telnet and Looking Glass access.

Multiple memory leaks in Cisco IOS 12.0 through 12.4 allow remote attackers to cause a denial of service (device crash) via a malformed SIP packet, aka (1) CSCsf11855, (2) CSCeb21064, (3) CSCse40276, (4) CSCse68355, (5) CSCsf30058, (6) CSCsb24007, and (7) CSCsc60249.

Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service (device crash) via (1) "abnormal" MGCP messages, aka CSCsd81407; and (2) a large facsimile packet, aka CSCej20505.

Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service via (1) a malformed MGCP packet, which causes a device hang, aka CSCsf08998; a malformed H.323 packet, which causes a device crash, as identified by (2) CSCsi60004 with Proxy Unregistration and (3) CSCsg70474; and a malformed Real-time Transport Protocol (RTP) packet, which causes a device crash, as identified by (4) CSCse68138, related to VOIP RTP Lib, and (5) CSCse05642, related to I/O memory corruption.

Unspecified vulnerability in Cisco IOS and Cisco IOS XR 12.x up to 12.3, including some versions before 12.3(15) and 12.3(14)T, allows remote attackers to obtain sensitive information (partial packet contents) or cause a denial of service (router or component crash) via crafted IPv6 packets with a Type 0 routing header.

Unspecified vulnerability in Cisco IOS 12.0 through 12.4 allows remote attackers to execute arbitrary code via a malformed SIP packet, aka CSCsi80749.

Buffer overflow in the Next Hop Resolution Protocol (NHRP) functionality in Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service (restart) and execute arbitrary code via a crafted NHRP packet.