Cisco IOS before 15.2(4)S6 does not initialize an unspecified variable, which might allow remote authenticated users to cause a denial of service (CPU consumption, watchdog timeout, crash) by walking specific SNMP objects.

A vulnerability in the Cisco Cluster Management Protocol (CMP) processing code in Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an affected device or remotely execute code with elevated privileges. The Cluster Management Protocol utilizes Telnet internally as a signaling and command protocol between cluster members. The vulnerability is due to the combination of two factors: (1) the failure to restrict the use of CMP-specific Telnet options only to internal, local communications between cluster members and instead accept and process such options over any Telnet connection to an affected device; and (2) the incorrect processing of malformed CMP-specific Telnet options. An attacker could exploit this vulnerability by sending malformed CMP-specific Telnet options while establishing a Telnet session with an affected Cisco device configured to accept Telnet connections. An exploit could allow an attacker to execute arbitrary code and obtain full control of the device or cause a reload of the affected device. This affects Catalyst switches, Embedded Service 2020 switches, Enhanced Layer 2 EtherSwitch Service Module, Enhanced Layer 2/3 EtherSwitch Service Module, Gigabit Ethernet Switch Module (CGESM) for HP, IE Industrial Ethernet switches, ME 4924-10GE switch, RF Gateway 10, and SM-X Layer 2/3 EtherSwitch Service Module. Cisco Bug IDs: CSCvd48893.

The DNS forwarder in Cisco IOS 12.0 through 12.4 and 15.0 through 15.6 and IOS XE 3.1 through 3.15 allows remote attackers to obtain sensitive information from process memory or cause a denial of service (data corruption or device reload) via a crafted DNS response, aka Bug ID CSCup90532.

The Zone-Based Firewall (ZBFW) functionality in Cisco IOS, possibly 15.4 and earlier, and IOS XE, possibly 3.13 and earlier, mishandles zone checking for existing sessions, which allows remote attackers to bypass intended resource-access restrictions via spoofed traffic that matches one of these sessions, aka Bug IDs CSCun94946 and CSCun96847.

The Data in Motion (DMo) application in Cisco IOS 15.6(1)T and IOS XE, when the IOx feature set is enabled, allows remote attackers to cause a denial of service via a crafted packet, aka Bug IDs CSCuy82904, CSCuy82909, and CSCuy82912.

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.

Race condition in the Common Classification Engine (CCE) in the Measurement, Aggregation, and Correlation Engine (MACE) implementation in Cisco IOS 15.4(2)T3 and earlier allows remote attackers to cause a denial of service (device reload) via crafted network traffic that triggers improper handling of the timing of process switching and Cisco Express Forwarding (CEF) switching, aka Bug ID CSCuj96752.

Race condition in the object-group ACL feature in Cisco IOS 15.5(2)T and earlier allows remote attackers to bypass intended access restrictions via crafted network traffic that triggers improper handling of the timing of process switching and Cisco Express Forwarding (CEF) switching, aka Bug ID CSCun21071.

Race condition in the Measurement, Aggregation, and Correlation Engine (MACE) implementation in Cisco IOS 15.4(2)T3 and earlier allows remote attackers to cause a denial of service (device reload) via crafted network traffic that triggers improper handling of the timing of process switching and Cisco Express Forwarding (CEF) switching, aka Bug ID CSCul48736.

The Zone-Based Firewall implementation in Cisco IOS 15.4(2)T3 and earlier allows remote attackers to cause a denial of service (device reload) via crafted network traffic that triggers incorrect kernel-timer handling, aka Bug ID CSCuh25672.

The Network-Based Application Recognition (NBAR) protocol implementation in Cisco IOS 15.3(100)M and earlier on Cisco 2900 Integrated Services Router (aka Cisco Internet Router) devices allows remote attackers to cause a denial of service (NBAR process hang) via IPv4 packets, aka Bug ID CSCuo73682.

The Locator/ID Separation Protocol (LISP) implementation in Cisco IOS 15.3(3)S and earlier and IOS XE does not properly validate parameters in ITR control messages, which allows remote attackers to cause a denial of service (CEF outage and packet drops) via malformed messages, aka Bug ID CSCun73782.

Cisco IOS before 15.3(2)S allows remote attackers to bypass interface ACL restrictions in opportunistic circumstances by sending IPv6 packets in an unspecified scenario in which expected packet drops do not occur for "a small percentage" of the packets, aka Bug ID CSCty73682.

Cisco IOS Unified Border Element (CUBE) in Cisco IOS before 15.3(2)T allows remote authenticated users to cause a denial of service (input queue wedge) via a crafted series of RTCP packets, aka Bug ID CSCuc42518.

Cisco IOS before 15.3(1)T, when media flow-around is not used, allows remote attackers to cause a denial of service (media loops and stack memory corruption) via VoIP traffic, aka Bug ID CSCub45809.

Unspecified vulnerability in Cisco IOS before 15.3(2)T on AS5400 devices allows remote authenticated users to cause a denial of service (spurious errors) via unknown vectors, aka Bug ID CSCub61009.

The ACL implementation in Cisco IOS before 15.1(1)SY on Catalyst 6500 and 7600 devices allows local users to cause a denial of service (device reload) via a "no object-group" command followed by an object-group command, aka Bug ID CSCts16133.

Cisco IOS before 15.1(1)SY1 allows remote authenticated users to cause a denial of service (device reload) by establishing a VPN session and then sending malformed IKEv2 packets, aka Bug ID CSCub39268.

The Flex-VPN load-balancing feature in the ipsec-ikev2 implementation in Cisco IOS before 15.1(1)SY3 does not require authentication, which allows remote attackers to trigger the forwarding of VPN traffic to an attacker-controlled destination, or the discarding of this traffic, by arranging for an arbitrary device to become a cluster member, aka Bug ID CSCub93641.

The ios-authproxy implementation in Cisco IOS before 15.1(1)SY3 allows remote attackers to cause a denial of service (webauth and HTTP service outage) via vectors that trigger incorrectly terminated HTTP sessions, aka Bug ID CSCtz99447.