The NTP implementation in Cisco IOS 12.0 through 12.4 and 15.0 through 15.1, and IOS XE 2.1 through 3.3, does not properly handle encapsulation of multicast NTP packets within MSDP SA messages, which allows remote attackers to cause a denial of service (device reload) by leveraging an MSDP peer relationship, aka Bug ID CSCuc81226.

Cisco IOS 12.2 through 12.4 and 15.0 through 15.3, and IOS XE 2.1 through 3.9, allows remote attackers to cause a denial of service (device reload) via crafted DHCP packets that are processed locally by a (1) server or (2) relay agent, aka Bug ID CSCug31561.

Race condition in the IPv6 virtual fragmentation reassembly (VFR) implementation in Cisco IOS 12.2 through 12.4 and 15.0 through 15.3 allows remote attackers to cause a denial of service (device reload or hang) via fragmented IPv6 packets, aka Bug ID CSCud64812.

The Protocol Translation (PT) functionality in Cisco IOS 12.3 through 12.4 and 15.0 through 15.3, when one-step port-23 translation or a Telnet-to-PAD ruleset is configured, does not properly validate TCP connection information, which allows remote attackers to cause a denial of service (device reload) via an attempted connection to a PT resource, aka Bug ID CSCtz35999.

The SIP implementation in Cisco Unified Communications Manager (CUCM) 6.x and 7.x before 7.1(5b)su5, 8.x before 8.5(1)su4, and 8.6 before 8.6(2a)su1; Cisco IOS 12.2 through 12.4 and 15.0 through 15.2; and Cisco IOS XE 3.3.xSG before 3.3.1SG, 3.4.xS, and 3.5.xS allows remote attackers to cause a denial of service (service crash or device reload) via a crafted SIP message containing an SDP session description, aka Bug IDs CSCtw66721, CSCtj33003, and CSCtw84664.

The Intrusion Prevention System (IPS) feature in Cisco IOS 12.3 through 12.4 and 15.0 through 15.2, in certain configurations of enabled categories and missing signatures, allows remote attackers to cause a denial of service (device reload) via DNS packets, aka Bug ID CSCtw55976.

The DHCPv6 server in Cisco IOS 12.2 through 12.4 and 15.0 through 15.2 and IOS XE 2.1.x through 2.6.x, 3.1.xS before 3.1.4S, 3.1.xSG and 3.2.xSG before 3.2.5SG, 3.2.xS, 3.2.xXO, 3.3.xS, and 3.3.xSG before 3.3.1SG allows remote attackers to cause a denial of service (device reload) via a malformed DHCPv6 packet, aka Bug ID CSCto57723.

Cisco IOS 12.3 and 12.4 on Aironet access points allows remote attackers to cause a denial of service (radio-interface input-queue hang) via IAPP 0x3281 packets, aka Bug ID CSCtc12426.

dot11t/t_if_dot11_hal_ath.c in Cisco IOS 12.3, 12.4, 15.0, and 15.1 allows remote attackers to cause a denial of service (assertion failure and reboot) via 802.11 wireless traffic, as demonstrated by a video call from Apple iOS 5.0 on an iPhone 4S, aka Bug ID CSCtt94391.

Cisco IOS 12.2 through 12.4 and 15.0 does not recognize the vrf-also keyword during enforcement of access-class commands, which allows remote attackers to establish TELNET connections from arbitrary source IP addresses via a standard TELNET client, aka Bug ID CSCsi77774.