Cisco IOS Xr 5.2.1

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.

Memory leak in Cisco IOS XR 5.1.x through 5.1.3, 5.2.x through 5.2.5, and 5.3.x through 5.3.2 on ASR 9001 devices allows remote attackers to cause a denial of service (control-plane protocol outage) via crafted fragmented packets, aka Bug ID CSCux26791.

Cisco IOS XR 5.x through 5.2.5 on NCS 6000 devices allows remote attackers to cause a denial of service (timer consumption and Route Processor reload) via crafted SSH traffic, aka Bug ID CSCux76819.

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.

Cisco IOS XR 5.0.1 and 5.2.1 on Network Convergence System (NCS) 6000 devices and 5.1.3 and 5.1.4 on Carrier Routing System X (CRS-X) devices allows remote attackers to cause a denial of service (line-card reload) via malformed IPv6 packets with extension headers, aka Bug ID CSCuq95241.

The SCP and SFTP modules in Cisco IOS XR 5.0.0 through 5.2.5 on Network Convergence System 6000 devices use weak permissions for system files, which allows remote authenticated users to cause a denial of service (overwrite) via unspecified vectors, aka Bug ID CSCuw75848.

Cisco IOS XR 5.2.1 allows remote attackers to cause a denial of service (ipv6_io service reload) via a malformed IPv6 packet, aka Bug ID CSCuq95565.

The Local Packet Transport Services (LPTS) implementation in Cisco IOS XR 5.1.2, 5.1.3, 5.2.1, and 5.2.2 on ASR9k devices makes incorrect decisions about the opening of TCP and UDP ports during the processing of flow base entries, which allows remote attackers to cause a denial of service (resource consumption) by sending traffic to these ports continuously, aka Bug ID CSCur88273.

A vulnerability in the UDP forwarding code of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to bypass configured management plane protection policies and access the Simple Network Management Plane (SNMP) server of an affected device. This vulnerability is due to incorrect UDP forwarding programming when using SNMP with management plane protection. An attacker could exploit this vulnerability by attempting to perform an SNMP operation using broadcast as the destination address that could be processed by an affected device that is configured with an SNMP server. A successful exploit could allow the attacker to communicate to the device on the configured SNMP ports. Although an unauthenticated attacker could send UDP datagrams to the configured SNMP port, only an authenticated user can retrieve or modify data using SNMP requests.