Multiple Buffer Overflow vulnerabilities in the Link Layer Discovery Protocol (LLDP) subsystem of Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition or execute arbitrary code with elevated privileges on an affected device. Cisco Bug IDs: CSCuo17183, CSCvd73487.

A vulnerability in the IPv6 subsystem of Cisco IOS XR Software Release 5.3.4 for the Cisco Aggregation Services Router (ASR) 9000 Series could allow an unauthenticated, remote attacker to trigger a reload of one or more Trident-based line cards, resulting in a denial of service (DoS) condition. The vulnerability is due to incorrect handling of IPv6 packets with a fragment header extension. An attacker could exploit this vulnerability by sending IPv6 packets designed to trigger the issue either to or through the Trident-based line card. A successful exploit could allow the attacker to trigger a reload of Trident-based line cards, resulting in a DoS during the period of time the line card takes to restart. This vulnerability affects Cisco Aggregation Services Router (ASR) 9000 Series when the following conditions are met: The router is running Cisco IOS XR Software Release 5.3.4, and the router has installed Trident-based line cards that have IPv6 configured. A software maintenance upgrade (SMU) has been made available that addresses this vulnerability. The fix has also been incorporated into service pack 7 for Cisco IOS XR Software Release 5.3.4. Cisco Bug IDs: CSCvg46800.

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.

Cisco IOS XR 4.3(.2) and earlier on ASR 9000 devices does not properly perform NetFlow sampling of packets with multicast destination MAC addresses, which allows remote attackers to cause a denial of service (chip and card hangs) via a crafted packet, aka Bug ID CSCup77750.

Cisco IOS XR 4.3(.2) and earlier on ASR 9000 devices does not properly perform NetFlow sampling of IP packets, which allows remote attackers to cause a denial of service (chip and card hangs) via malformed (1) IPv4 or (2) IPv6 packets, aka Bug ID CSCuo68417.

Cisco IOS XR 4.3.4 and earlier on ASR 9000 devices, when bridge-group virtual interface (BVI) routing is enabled, allows remote attackers to cause a denial of service (chip and card hangs) via a series of crafted MPLS packets, aka Bug ID CSCuo91149.

Cisco IOS XR on Trident line cards in ASR 9000 devices lacks a static punt policer, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted packets, aka Bug ID CSCun83985.

Cisco IOS XR 4.1.2 through 5.1.1 on ASR 9000 devices, when a Trident-based line card is used, allows remote attackers to cause a denial of service (NP chip and line card reload) via malformed IPv6 packets, aka Bug ID CSCun71928.