The Zone-Based Firewall (ZFW) feature in Cisco IOS 15.1 through 15.2, when content filtering or HTTP ALG inspection is enabled, allows remote attackers to cause a denial of service (device reload or hang) via crafted IPv4 HTTP traffic, aka Bug ID CSCtx56174.

The T1/E1 driver-queue functionality in Cisco IOS 12.2 and 15.0 through 15.3, when an HDLC32 driver is used, allows remote attackers to cause a denial of service (interface queue wedge) via bursty network traffic, aka Bug ID CSCub67465.

Cisco IOS 15.0 through 15.3 and IOS XE 3.2 through 3.8, when a VRF interface exists, allows remote attackers to cause a denial of service (interface queue wedge) via crafted UDP RSVP packets, aka Bug ID CSCuf17023.

The DNS-over-TCP implementation in Cisco IOS 12.2 and 15.0 through 15.3, when NAT is used, allows remote attackers to cause a denial of service (device reload) via a crafted IPv4 DNS TCP stream, aka Bug ID CSCtn53730.

The DNS-over-TCP implementation in Cisco IOS 12.2 and 15.0 through 15.3, when NAT is used, allows remote attackers to cause a denial of service (device reload) via a crafted IPv4 DNS TCP stream, aka Bug ID CSCuf28733.

The PPTP implementation in Cisco IOS 12.2 and 15.0 through 15.3, when NAT is used, allows remote attackers to cause a denial of service (device reload) via crafted TCP port-1723 packets, aka Bug ID CSCtq14817.

The PPTP-ALG component in CRS Carrier Grade Services Engine (CGSE) and ASR 9000 Integrated Service Module (ISM) in Cisco IOS XR allows remote attackers to cause a denial of service (module reset) via crafted packet streams, aka Bug ID CSCue91963.

The remember feature in the DHCP server in Cisco IOS allows remote attackers to cause a denial of service (device reload) by acquiring a lease and then sending a DHCPRELEASE message, aka Bug ID CSCuh46822.

The UDP process in Cisco IOS XR 4.3.1 does not free packet memory upon detecting full packet queues, which allows remote attackers to cause a denial of service (memory consumption) via UDP packets to listening ports, aka Bug ID CSCue69413.

Cisco IOS on Catalyst 3750X switches has default Service Module credentials, which makes it easier for local users to gain privileges via a Service Module login, aka Bug ID CSCue92286.

The OSPF functionality in Cisco IOS and IOS XE allows remote attackers to cause a denial of service (device reload) via crafted options in an LSA type 11 packet, aka Bug ID CSCui21030.

Cisco IOS XE 3.4 before 3.4.2S and 3.5 before 3.5.1S on 1000 ASR devices allows remote attackers to cause a denial of service (device reload) via malformed ICMP error packets associated with a (1) TCP or (2) UDP session that is under inspection by the Zone-Based Firewall (ZBFW) component, aka Bug ID CSCtt26470.

The PPTP ALG implementation in Cisco IOS XE 3.9 before 3.9.2S on 1000 ASR devices allows remote attackers to cause a denial of service (device reload) by sending many PPTP packets over NAT, aka Bug ID CSCuh19936.

The TCP reassembly feature in Cisco IOS XE 3.7 before 3.7.3S and 3.8 before 3.8.1S on 1000 ASR devices allows remote attackers to cause a denial of service (device reload) via large TCP packets that are processed by the (1) NAT or (2) ALG component, aka Bug ID CSCud72509.

Cisco IOS XE 3.9 before 3.9.2S on 1000 ASR devices allows remote attackers to cause a denial of service (device reload) by sending malformed EoGRE packets over (1) IPv4 or (2) IPv6, aka Bug ID CSCuf08269.

The IKEv2 implementation in Cisco IOS, when AES-GCM or AES-GMAC is used, allows remote attackers to bypass certain IPsec anti-replay features via IPsec tunnel traffic, aka Bug ID CSCuj47795.

Cisco IOS XR 3.8.1 through 4.2.0 does not properly process fragmented packets within the RP-A, RP-B, PRP, and DRP-B route-processor components, which allows remote attackers to cause a denial of service (transmission outage) via (1) IPv4 or (2) IPv6 traffic, aka Bug ID CSCuh30380.

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.

Multiple memory leaks in Cisco IOS 15.1 before 15.1(4)M7 allow remote attackers to cause a denial of service (memory consumption or device reload) by sending a crafted SIP message over (1) IPv4 or (2) IPv6, aka Bug IDs CSCuc42558 and CSCug25383.

The OSPFv3 functionality in Cisco IOS XR 5.1 allows remote attackers to cause a denial of service (process crash) via a malformed LSA Type-1 packet, aka Bug ID CSCuj82176.