Cisco IOS 12.2, 12.4, 15.0, 15.2, and 15.3, when a VRF interface is configured, allows remote attackers to cause a denial of service (interface queue wedge) via crafted ICMPv4 packets, aka Bug ID CSCsi02145.

Cisco IOS 12.0, 12.2, 12.4, 15.0, 15.1, 15.2, and 15.3 and IOS XE 2.x and 3.x before 3.7.4S; 3.2.xSE and 3.3.xSE before 3.3.2SE; 3.3.xSG and 3.4.xSG before 3.4.4SG; and 3.8.xS, 3.9.xS, and 3.10.xS before 3.10.1S allow remote attackers to cause a denial of service (device reload) via malformed RSVP packets, aka Bug ID CSCui11547.

The TCP Input module in Cisco IOS 12.2 through 12.4 and 15.0 through 15.4, when NAT is used, allows remote attackers to cause a denial of service (memory consumption or device reload) via crafted TCP packets, aka Bug IDs CSCuh33843 and CSCuj41494.

The Application Layer Gateway (ALG) module in Cisco IOS 12.2 through 12.4 and 15.0 through 15.4, when NAT is used, allows remote attackers to cause a denial of service (device reload) via crafted DNS packets, aka Bug ID CSCue00996.

Cisco IOS 12.4(24)MDB9 and earlier on Content Services Gateway (CSG) devices does not properly implement the "parse error drop" feature, which allows remote attackers to bypass intended access restrictions via a crafted series of packets, aka Bug ID CSCug90143.

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.

Memory leak in Cisco IOS 12.2, 12.4, 15.0, and 15.1, when Zone-Based Policy Firewall SIP application layer gateway inspection is enabled, allows remote attackers to cause a denial of service (memory consumption or device reload) via malformed SIP messages, aka Bug ID CSCtl99174.

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.