A vulnerability in the TCP flags inspection feature for access control lists (ACLs) on Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass protection offered by a configured ACL on an affected device. The vulnerability is due to incorrect processing of the ACL applied to an interface of an affected device when Cisco Express Forwarding load balancing using the 3-tuple hash algorithm is enabled. An attacker could exploit this vulnerability by sending traffic through an affected device that should otherwise be denied by the configured ACL. An exploit could allow the attacker to bypass protection offered by a configured ACL on the affected device. There are workarounds that address this vulnerability. Affected Cisco IOS XR versions are: Cisco IOS XR Software Release 5.1.1 and later till first fixed. First Fixed Releases: 6.5.2 and later, 6.6.1 and later.

A vulnerability in the TFTP service of Cisco Network Convergence System 1000 Series software could allow an unauthenticated, remote attacker to retrieve arbitrary files from the targeted device, possibly resulting in information disclosure. The vulnerability is due to improper validation of user-supplied input within TFTP requests processed by the affected software. An attacker could exploit this vulnerability by using directory traversal techniques in malicious requests sent to the TFTP service on a targeted device. An exploit could allow the attacker to retrieve arbitrary files from the targeted device, resulting in the disclosure of sensitive information. This vulnerability affects Cisco IOS XR Software releases prior to Release 6.5.2 for Cisco Network Convergence System 1000 Series devices when the TFTP service is enabled.

A vulnerability in the implementation of Border Gateway Protocol (BGP) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain BGP update messages. An attacker could exploit this vulnerability by sending BGP update messages that include a specific, malformed attribute to be processed by an affected system. A successful exploit could allow the attacker to cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit this vulnerability, the malicious BGP update message would need to come from a configured, valid BGP peer, or would need to be injected by the attacker into the victim's BGP network on an existing, valid TCP connection to a BGP peer.

The SNMPv2 implementation in Cisco IOS XR allows remote authenticated users to cause a denial of service (snmpd daemon reload) via a malformed SNMP packet, aka Bug ID CSCur25858.

Cisco IOS XR allows remote attackers to cause a denial of service (RSVP process reload) via a malformed RSVP packet, aka Bug ID CSCur69192.

Cisco IOS XR allows remote attackers to cause a denial of service (RSVP process reload) via a malformed RSVP packet, aka Bug ID CSCub63710.

Cisco IOS XR allows remote attackers to cause a denial of service (LISP process reload) by establishing many LISP TCP sessions, aka Bug ID CSCuq90378.

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.

The CLI in Cisco IOS XR allows remote authenticated users to obtain sensitive information via unspecified commands, aka Bug IDs CSCuq42336, CSCuq76853, CSCuq76873, and CSCuq45383.

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.

The DHCPv6 implementation in Cisco IOS XR allows remote attackers to cause a denial of service (device crash) via a malformed packet, aka Bug IDs CSCum85558, CSCum20949, CSCul61849, and CSCul71149.

The DHCPv6 implementation in Cisco IOS XR allows remote attackers to cause a denial of service (process hang) via a malformed packet, aka Bug ID CSCul80924.

Cisco IOS XR does not properly throttle ICMPv6 redirect packets, which allows remote attackers to cause a denial of service (IPv4 and IPv6 transit outage) via crafted redirect messages, aka Bug ID CSCum14266.

The SNMP module in Cisco IOS XR allows remote attackers to cause a denial of service (process reload) via a request for an unspecified MIB, aka Bug ID CSCuh43144.

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 RIP process in Cisco IOS XR allows remote attackers to cause a denial of service (process crash) via a crafted version-2 RIP packet, aka Bug ID CSCue46731.

Memory leak in the SNMP process in Cisco IOS XR allows remote attackers to cause a denial of service (memory consumption or process reload) by sending many port-162 UDP packets, aka Bug ID CSCug80345.

The SNMP module in Cisco IOS XR allows remote authenticated users to cause a denial of service (process restart) via crafted SNMP packets, aka Bug ID CSCue69472.

Memory leak in the SNMP module in Cisco IOS XR allows remote authenticated users to cause a denial of service (memory consumption and process restart) via crafted SNMP packets, aka Bug ID CSCue31546.

The traffic engineering (TE) processing subsystem in Cisco IOS XR allows remote attackers to cause a denial of service (process restart) via crafted TE packets, aka Bug ID CSCue04000.