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.
Cisco IOS XR 5.1.3 allows remote attackers to cause a denial of service (process reload) via crafted MPLS Label Distribution Protocol (LDP) packets, aka Bug ID CSCuu77478.
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.
The Neighbor Discovery (ND) protocol implementation in the IPv6 stack in Cisco IOS XE 2.1 through 3.17S, IOS XR 2.0.0 through 5.3.2, and NX-OS allows remote attackers to cause a denial of service (packet-processing outage) via crafted ND messages, aka Bug ID CSCuz66542, as exploited in the wild in May 2016.
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.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.
Multiple vulnerabilities in the ingress packet processing function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory. Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dos-WwDdghs2