snmpd in Cisco IOS XR 5.1 and earlier allows remote authenticated users to cause a denial of service (process reload) via a malformed SNMPv2 packet, aka Bug ID CSCun67791.

Cisco IOS XR allows local users to cause a denial of service (Silicon Packet Processor memory corruption, improper mutex handling, and device reload) by starting an outbound flood of large ICMP Echo Request packets and stopping this with a CTRL-C sequence, aka Bug ID CSCui60347.

The BGP implementation in Cisco IOS 15.2, IOS XE 3.5.xS before 3.5.2S, and IOS XR 4.1.0 through 4.2.2 allows remote attackers to cause a denial of service (multiple connection resets) by leveraging a peer relationship and sending a malformed attribute, aka Bug IDs CSCtt35379, CSCty58300, CSCtz63248, and CSCtz62914.

Unspecified vulnerability in the sshd_child_handler process in the SSH server in Cisco IOS XR 3.4.1 through 3.7.0 allows remote attackers to cause a denial of service (process crash and memory consumption) via a crafted SSH2 packet, aka Bug ID CSCsu10574.

Cisco IOS XR 3.8.1 and earlier allows remote authenticated users to cause a denial of service (process crash) via vectors involving a BGP UPDATE message with many AS numbers prepended to the AS path.

Cisco IOS XR 3.8.1 and earlier allows remote attackers to cause a denial of service (process crash) via a long BGP UPDATE message, as demonstrated by a message with many AS numbers in the AS Path Attribute.

Cisco IOS XR 3.4.0 through 3.8.1 allows remote attackers to cause a denial of service (session reset) via a BGP UPDATE message with an invalid attribute, as demonstrated in the wild on 17 August 2009.

The TCP implementation in (1) Linux, (2) platforms based on BSD Unix, (3) Microsoft Windows, (4) Cisco products, and probably other operating systems allows remote attackers to cause a denial of service (connection queue exhaustion) via multiple vectors that manipulate information in the TCP state table, as demonstrated by sockstress.