A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to the improper translation of H.323 messages that use the Registration, Admission, and Status (RAS) protocol and are sent to an affected device via IPv4 packets. An attacker could exploit this vulnerability by sending a crafted H.323 RAS packet through an affected device. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition. This vulnerability affects Cisco devices that are configured to use an application layer gateway with NAT (NAT ALG) for H.323 RAS messages. By default, a NAT ALG is enabled for H.323 RAS messages. Cisco Bug IDs: CSCvc57217.
Cisco IOS XR through 5.3.2 mishandles Local Packet Transport Services (LPTS) flow-base entries, which allows remote attackers to cause a denial of service (session drop) by making many connection attempts to open TCP ports, aka Bug ID CSCux95576.
The DHCPv6 server in Cisco IOS on ASR 9000 devices with software 5.2.0 Base allows remote attackers to cause a denial of service (process reset) via crafted packets, aka Bug ID CSCun72171.
The DHCPv6 server in Cisco IOS on ASR 9000 devices with software 5.2.0 Base allows remote attackers to cause a denial of service (process reset) via crafted packets, aka Bug ID CSCun36525.
The Concurrent Data Management Replication process in Cisco IOS XR 5.3.0 on ASR 9000 devices allows remote attackers to cause a denial of service (BGP process reload) via malformed BGPv4 packets, aka Bug ID CSCur70670.
Cisco IOS XR 5.3.1 on ASR 9000 devices allows remote attackers to cause a denial of service (NPU chip reset or line-card reload) by sending crafted IEEE 802.3x flow-control PAUSE frames on the local network, aka Bug ID CSCut19959.
Cisco IOS XR 4.3.4 through 5.3.0 on ASR 9000 devices, when uRPF, PBR, QoS, or an ACL is configured, does not properly handle bridge-group virtual interface (BVI) traffic, which allows remote attackers to cause a denial of service (chip and card hangs and reloads) by triggering use of a BVI interface for IPv4 packets, aka Bug ID CSCur62957.
Cisco ASR 9000 devices with software 5.3.0.BASE do not recognize that certain ACL entries have a single-host constraint, which allows remote attackers to bypass intended network-resource access restrictions by using an address that was not supposed to have been allowed, aka Bug ID CSCur28806.
The DHCPv4 server in Cisco IOS XR 5.2.2 on ASR 9000 devices allows remote attackers to cause a denial of service (service outage) via a flood of crafted DHCP packets, aka Bug ID CSCup67822.
Cisco IOS XR on ASR 9000 devices does not properly use compression for port-range and address-range encoding, which allows remote attackers to bypass intended Typhoon line-card ACL restrictions via transit traffic, aka Bug ID CSCup30133.