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.

Cisco IOS 12.2 through 12.4 and 15.0 through 15.2 and IOS XE 2.1.x through 2.6.x and 3.1.xS before 3.1.2S, 3.2.xS through 3.4.xS before 3.4.2S, 3.5.xS before 3.5.1S, and 3.1.xSG and 3.2.xSG before 3.2.2SG, when AAA authorization is enabled, allow remote authenticated users to bypass intended access restrictions and execute commands via a (1) HTTP or (2) HTTPS session, aka Bug ID CSCtr91106.

The Neighbor Discovery (ND) protocol implementation in Cisco IOS on unspecified switches allows remote attackers to bypass the Router Advertisement Guarding functionality via a fragmented IPv6 packet in which the Router Advertisement (RA) message is contained in the second fragment, as demonstrated by (1) a packet in which the first fragment contains a long Destination Options extension header or (2) a packet in which the first fragment contains an ICMPv6 Echo Request message.

CallManager Express (CME) on Cisco IOS before 15.0(1)XA allows remote authenticated users to cause a denial of service (device crash) by using an extension mobility (EM) phone to interact with the menu for SNR number changes, aka Bug ID CSCta63555.

Unspecified vulnerability in Cisco IOS 12.0 through 12.4, IOS XE 2.1.x through 2.3.x before 2.3.2, and IOS XR 3.2.x through 3.4.3, when Multiprotocol Label Switching (MPLS) and Label Distribution Protocol (LDP) are enabled, allows remote attackers to cause a denial of service (device reload or process restart) via a crafted LDP packet, aka Bug IDs CSCsz45567 and CSCsj25893.

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.

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.

Stack-based buffer overflow in the Line Printer Daemon (LPD) in Cisco IOS before 12.2(18)SXF11, 12.4(16a), and 12.4(2)T6 allow remote attackers to execute arbitrary code by setting a long hostname on the target system, then causing an error message to be printed, as demonstrated by a telnet session to the LPD from a source port other than 515.

Unspecified vulnerability in Cisco IOS 12.0 through 12.4 allows context-dependent attackers to cause a denial of service (device restart and BGP routing table rebuild) via certain regular expressions in a "show ip bgp regexp" command. NOTE: unauthenticated remote attacks are possible in environments with anonymous telnet and Looking Glass access.