A vulnerability in the Cisco Encrypted Traffic Analytics (ETA) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to a logic error that exists when handling a malformed incoming packet, leading to access to an internal data structure after it has been freed. An attacker could exploit this vulnerability by sending crafted, malformed IP packets to an affected device. A successful exploit could allow the attacker to cause an affected device to reload, resulting in a DoS condition.

Unspecified vulnerability in the Wireless LAN Controller (WLC) TSEC driver in the Cisco 4400 WLC, Cisco Catalyst 6500 and 7600 Wireless Services Module (WiSM), and Cisco Catalyst 3750 Integrated Wireless LAN Controller with software 4.x before 4.2.176.0 and 5.x before 5.1 allows remote attackers to cause a denial of service (device crash or hang) via unknown IP packets.

Memory leak in Cisco Unified Communications Manager IM and Presence Service before 8.6(5)SU1 and 9.x before 9.1(2), and Cisco Unified Presence, allows remote attackers to cause a denial of service (memory and CPU consumption) by making many TCP connections to port (1) 5060 or (2) 5061, aka Bug ID CSCud84959.

Cisco Prime Central for Hosted Collaboration Solution (HCS) Assurance 8.6 and 9.x before 9.2(1) allows remote attackers to cause a denial of service (memory consumption) via a flood of TCP packets to port (1) 61615 or (2) 61616, aka Bug ID CSCtz90114.

Memory leak in Cisco Prime Central for Hosted Collaboration Solution (HCS) Assurance 8.6 and 9.x before 9.2(1) allows remote attackers to cause a denial of service (memory consumption) via a flood of TCP packets, aka Bug ID CSCub59158.

The do_change_cipher_spec function in OpenSSL 0.9.6c to 0.9.6k, and 0.9.7a to 0.9.7c, allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that triggers a null dereference.

Cisco Intrusion Prevention System (IPS) Software on IPS NME devices before 7.0(9)E4 allows remote attackers to cause a denial of service (device reload) via malformed IPv4 packets that trigger incorrect memory allocation, aka Bug ID CSCua61977.

Extended Interior Gateway Routing Protocol (EIGRP), as implemented in Cisco IOS 11.3 through 12.2 and other products, allows remote attackers to cause a denial of service (flood) by sending a large number of spoofed EIGRP neighbor announcements, which results in an ARP storm on the local network.

The management GUI in the web framework in IronPort AsyncOS on Cisco Web Security Appliance devices before 7.1.3-013, 7.5 before 7.5.0-838, and 7.7 before 7.7.0-602; Email Security Appliance devices before 7.1.5-106 and 7.3, 7.5, and 7.6 before 7.6.3-019; and Content Security Management Appliance devices before 7.9.1-102 and 8.0 before 8.0.0-404 allows remote attackers to cause a denial of service (system hang) via a series of (1) HTTP or (2) HTTPS requests to a management interface, aka Bug IDs CSCzv58669, CSCzv63329, and CSCzv78669.

Cisco Adaptive Security Appliance (ASA) Software 8.4.x before 8.4(3) and 8.6.x before 8.6(1.3) does not properly manage memory upon an AnyConnect SSL VPN client disconnection, which allows remote attackers to cause a denial of service (memory consumption, and forwarding outage or system hang) via packets to the disconnected machine's IP address, aka Bug ID CSCtt36737.

Memory leak in Cisco Unified Communications Manager (Unified CM) 8.5(x) before 8.5(1)su6, 8.6(x) before 8.6(2a)su3, and 9.x before 9.1(1) allows remote attackers to cause a denial of service (service disruption) via a high rate of UDP packets, aka Bug ID CSCub85597.

The IronPort Spam Quarantine (ISQ) component in the web framework in IronPort AsyncOS on Cisco Email Security Appliance devices before 7.1.5-106 and 7.3, 7.5, and 7.6 before 7.6.3-019 and Content Security Management Appliance devices before 7.9.1-102 and 8.0 before 8.0.0-404 allows remote attackers to cause a denial of service (service crash or hang) via a high rate of TCP connection attempts, aka Bug IDs CSCzv25573 and CSCzv81712.

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper input validation when parsing HTTPS requests. An attacker could exploit this vulnerability by sending a malicious HTTPS request to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Cisco TelePresence TC Software before 5.1.7 and TE Software before 4.1.3 allow remote attackers to cause a denial of service (device reload) via crafted SIP packets, aka Bug ID CSCue01743.

A vulnerability in an API of the Call Bridge feature of Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper handling of large series of message requests. An attacker could exploit this vulnerability by sending a series of messages to the vulnerable API. A successful exploit could allow the attacker to cause the affected device to reload, dropping all ongoing calls and resulting in a DoS condition.

Cisco Prime Central for Hosted Collaboration Solution (HCS) Assurance 8.6 and 9.x before 9.2(1) allows remote attackers to cause a denial of service (disk consumption) via a flood of TCP packets to port 5400, leading to large error-log files, aka Bug ID CSCua42724.

Multiple vulnerabilities in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerabilities are due to incorrect processing of BGP update messages that contain crafted EVPN attributes. An attacker could exploit these vulnerabilities by sending BGP EVPN update messages with malformed attributes 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 these vulnerabilities, 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.

Cisco PIX firewall 5.x.x, and 6.3.1 and earlier, allows remote attackers to cause a denial of service (crash and reload) via an SNMPv3 message when snmp-server is set.

A vulnerability in the network stack of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability is due to an issue with allocating and freeing memory buffers in the network stack. An attacker could exploit this vulnerability by sending crafted TCP streams to an affected device in a sustained way. A successful exploit could cause the network stack of an affected device to run out of available buffers, impairing operations of control plane and management plane protocols, resulting in a DoS condition. Note: This vulnerability can be triggered only by traffic that is destined to an affected device and cannot be exploited using traffic that transits an affected device. Nexus 1000V Switch for Microsoft Hyper-V is affected in versions prior to 5.2(1)SM3(2.1). Nexus 1000V Switch for VMware vSphere is affected in versions prior to 5.2(1)SV3(4.1a). Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(6) and 9.2(2). Nexus 3500 Platform Switches are affected in versions prior to 6.0(2)A8(11), 7.0(3)I7(6), and 9.2(2). Nexus 3600 Platform Switches are affected in versions prior to 7.0(3)F3(5) and 9.2(2). Nexus 5500, 5600, and 6000 Series Switches are affected in versions prior to 7.1(5)N1(1b) and 7.3(5)N1(1). Nexus 7000 and 7700 Series Switches are affected in versions prior to 6.2(22. Nexus 9500 R-Series Line Cards and Fabric Modules are affected in versions prior to 7.0(3)F3(5) and 9.2(2). UCS 6200 and 6300 Series Fabric Interconnect are affected in versions prior to 3.2(3j) and 4.0(2a). UCS 6400 Series Fabric Interconnect are affected in versions prior to 4.0(2a).

A vulnerability in SSL/TLS message handler for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because incoming SSL/TLS packets are not properly processed. An attacker could exploit this vulnerability by sending a crafted SSL/TLS packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

Cisco IOS 12.4 allows remote attackers to cause a denial of service (device crash) via a normal, properly formed SSL packet that occurs during termination of an SSL session.

Cisco IOS 11.2.x and 12.0.x does not limit the size of its redirect table, which allows remote attackers to cause a denial of service (memory consumption) via spoofed ICMP redirect packets to the router.

A vulnerability in the Point-to-Point Tunneling Protocol (PPTP) VPN packet processing functionality in Cisco Aironet Access Points (APs) could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient validation of Generic Routing Encapsulation (GRE) frames that pass through the data plane of an affected AP. An attacker could exploit this vulnerability by associating to a vulnerable AP, initiating a PPTP VPN connection to an arbitrary PPTP VPN server, and sending a malicious GRE frame through the data plane of the AP. A successful exploit could allow the attacker to cause an internal process of the targeted AP to crash, which in turn would cause the AP to reload. The AP reload would cause a DoS condition for clients that are associated with the AP.

A vulnerability in the Network-Based Application Recognition (NBAR) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. This vulnerability is due to a parsing issue on DNS packets. An attacker could exploit these vulnerabilities by sending crafted DNS packets through routers that are running an affected version and have NBAR enabled. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition.

Multiple Cisco products are affected by a vulnerability in Snort rules that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.The vulnerability is due to improper handling of the Block with Reset or Interactive Block with Reset actions if a rule is configured without proper constraints. An attacker could exploit this vulnerability by sending a crafted IP packet to the affected device. A successful exploit could allow the attacker to cause through traffic to be dropped. Note: Only products with Snort3 configured and either a rule with Block with Reset or Interactive Block with Reset actions configured are vulnerable. Products configured with Snort2 are not vulnerable.

Multiple Cisco products are affected by a vulnerability in the way the Snort detection engine processes ICMP traffic that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper memory resource management while the Snort detection engine is processing ICMP packets. An attacker could exploit this vulnerability by sending a series of ICMP packets through an affected device. A successful exploit could allow the attacker to exhaust resources on the affected device, causing the device to reload.

A vulnerability in the Precision Time Protocol (PTP) feature of Cisco Nexus 5500, 5600, and 6000 Series Switches running Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a lack of protection against PTP frame flood attacks. An attacker could exploit this vulnerability by sending large streams of malicious IPv4 or IPv6 PTP traffic to the affected device. A successful exploit could allow the attacker to cause a DoS condition, impacting the traffic passing through the device.

A vulnerability in the ingress flow creation functionality of Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause the CPU to increase upwards of 100% utilization, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to incorrect handling of an internal software lock that could prevent other system processes from getting CPU cycles, causing a high CPU condition. An attacker could exploit this vulnerability by sending a steady stream of malicious IP packets that can cause connections to be created on the targeted device. A successful exploit could allow the attacker to exhaust CPU resources, resulting in a DoS condition during which traffic through the device could be delayed. This vulnerability applies to either IPv4 or IPv6 ingress traffic. This vulnerability affects Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliances (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliances (ASAv), Firepower 2100 Series Security Appliances, Firepower 4110 Security Appliances, Firepower 9300 ASA Security Modules. Cisco Bug IDs: CSCvf63718.

A vulnerability in the Secure Sockets Layer (SSL) packet reassembly functionality of the detection engine in Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause the detection engine to consume excessive system memory on an affected device, which could cause a denial of service (DoS) condition. The vulnerability is due to the affected software improperly handling changes to SSL connection states. An attacker could exploit this vulnerability by sending crafted SSL connections through an affected device. A successful exploit could allow the attacker to cause the detection engine to consume excessive system memory on the affected device, which could cause a DoS condition. The device may need to be reloaded manually to recover from this condition. This vulnerability affects Cisco Firepower System Software Releases 6.0.0 and later, running on any of the following Cisco products: Adaptive Security Appliance (ASA) 5500-X Series Firewalls with FirePOWER Services, Adaptive Security Appliance (ASA) 5500-X Series Next-Generation Firewalls, Advanced Malware Protection (AMP) for Networks, 7000 Series Appliances, Advanced Malware Protection (AMP) for Networks, 8000 Series Appliances, Firepower 4100 Series Appliances, FirePOWER 7000 Series Appliances, FirePOWER 8000 Series Appliances, Firepower 9300 Series Security Appliances, Firepower Threat Defense for Integrated Services Routers (ISRs), Firepower Threat Defense Virtual for VMware, Industrial Security Appliance 3000, Sourcefire 3D System Appliances. Cisco Bug IDs: CSCve23031.

A vulnerability in the web UI of Cisco FXOS and Cisco UCS Fabric Interconnect Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected system. The vulnerability is due to incorrect input validation in the web UI. An attacker could exploit this vulnerability by sending a malicious HTTP or HTTPS packet directed to the physical management interface of an affected system. A successful exploit could allow the attacker to cause the process to crash and possibly reload the device, resulting in a denial of service (DoS) condition on the affected system. This vulnerability affects Firepower 4100 Series Next-Generation Firewall, Firepower 9300 Security Appliance, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvb61398, CSCvb86799.

A vulnerability in the Network Time Protocol (NTP) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to excessive use of system resources when the affected device is logging a drop action for received MODE_PRIVATE (Mode 7) NTP packets. An attacker could exploit this vulnerability by flooding the device with a steady stream of Mode 7 NTP packets. A successful exploit could allow the attacker to cause high CPU and memory usage on the affected device, which could cause internal system processes to restart or cause the affected device to unexpectedly reload. Note: The NTP feature is enabled by default.

Cisco IOS 11.x and 12.0 through 12.2 allows remote attackers to cause a denial of service (traffic block) by sending a particular sequence of IPv4 packets to an interface on the device, causing the input queue on that interface to be marked as full.

A vulnerability in the IP Version 4 (IPv4) processing code of Cisco IOS XE Software running on Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches could allow an unauthenticated, remote attacker to cause high CPU utilization, traceback messages, or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain IPv4 packets. An attacker could exploit this vulnerability by sending specific IPv4 packets to an IPv4 address on an affected device. A successful exploit could allow the attacker to cause high CPU utilization, traceback messages, or a reload of the affected device that leads to a DoS condition. If the switch does not reboot when under attack, it would require manual intervention to reload the device. This vulnerability affects Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches that are running Cisco IOS XE Software Release 16.1.1 or later, until the first fixed release, and are configured with an IPv4 address. Cisco Bug IDs: CSCvd80714.

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a memory leak or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device to be processed. A successful exploit could cause an affected device to continuously consume memory and eventually reload, resulting in a DoS condition. Cisco Bug IDs: CSCvf22394.

A vulnerability in the Cisco IOS Software and Cisco IOS XE Software function that restores encapsulated option 82 information in DHCP Version 4 (DHCPv4) packets could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a Relay Reply denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of encapsulated option 82 information that it receives in DHCPOFFER messages from DHCPv4 servers. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device, which the device would then forward to a DHCPv4 server. When the affected software processes the option 82 information that is encapsulated in the response from the server, an error could occur. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvg62754.

A vulnerability in the web proxy functionality of Cisco AsyncOS Software for Cisco Web Security Appliances could allow an unauthenticated, remote attacker to exhaust system memory and cause a denial of service (DoS) condition on an affected system. The vulnerability exists because the affected software improperly manages memory resources for TCP connections to a targeted device. An attacker could exploit this vulnerability by establishing a high number of TCP connections to the data interface of an affected device via IPv4 or IPv6. A successful exploit could allow the attacker to exhaust system memory, which could cause the system to stop processing new connections and result in a DoS condition. System recovery may require manual intervention. Cisco Bug IDs: CSCvf36610.

A vulnerability in the FTP inspection engine of Cisco Adaptive Security (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of FTP data. An attacker could exploit this vulnerability by sending malicious FTP traffic through an affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

A vulnerability in the IPsec driver code of multiple Cisco IOS XE Software platforms and the Cisco ASA 5500-X Series Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause the device to reload. The vulnerability is due to improper processing of malformed IPsec Authentication Header (AH) or Encapsulating Security Payload (ESP) packets. An attacker could exploit this vulnerability by sending malformed IPsec packets to be processed by an affected device. An exploit could allow the attacker to cause a reload of the affected device.

A vulnerability in the Zone-Based Firewall code of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a device to reload. The vulnerability is due to the way fragmented packets are handled in the firewall code. An attacker could exploit this vulnerability by sending fragmented IP Version 4 or IP Version 6 packets through an affected device. An exploit could allow the attacker to cause the device to crash, resulting in a denial of service (DoS) condition. The following releases of Cisco IOS XE Software are vulnerable: Everest-16.4.1, Everest-16.4.2, Everest-16.5.1, Everest-16.5.1b, Everest-16.6.1, Everest-16.6.1a. Cisco Bug IDs: CSCvf60296.

A vulnerability in the implementation of Session Initiation Protocol (SIP) processing in Cisco Small Business SPA514G IP Phones could allow an unauthenticated, remote attacker to cause an affected device to become unresponsive, resulting in a denial of service (DoS) condition. The vulnerability is due to improper processing of SIP request messages by an affected device. An attacker could exploit this vulnerability by sending crafted SIP messages to an affected device. A successful exploit could allow the attacker to cause the affected device to become unresponsive, resulting in a DoS condition that persists until the device is restarted manually. Cisco has not released software updates that address this vulnerability. This vulnerability affects Cisco Small Business SPA514G IP Phones that are running firmware release 7.6.2SR2 or earlier.

A vulnerability in the Session Initiation Protocol (SIP) call-handling functionality of Cisco IP Phone 6800, 7800, and 8800 Series Phones with Multiplatform Firmware could allow an unauthenticated, remote attacker to cause an affected phone to reload unexpectedly, resulting in a temporary denial of service (DoS) condition. The vulnerability exists because the firmware of an affected phone incorrectly handles errors that could occur when an incoming phone call is not answered. An attacker could exploit this vulnerability by sending a set of maliciously crafted SIP packets to an affected phone. A successful exploit could allow the attacker to cause the affected phone to reload unexpectedly, resulting in a temporary DoS condition. This vulnerability affects Cisco IP Phone 6800, 7800, and 8800 Series Phones with Multiplatform Firmware if they are running a Multiplatform Firmware release prior to Release 11.1(2). Cisco Bug IDs: CSCvi24718.

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an NX-API system process to unexpectedly restart. The vulnerability is due to incorrect validation of the HTTP header of a request that is sent to the NX-API. An attacker could exploit this vulnerability by sending a crafted HTTP request to the NX-API on an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition in the NX-API service; however, the NX-OS device itself would still be available and passing network traffic. Note: The NX-API feature is disabled by default.

A vulnerability in the IPv6 processing code of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload. The vulnerability is due to incorrect handling of specific IPv6 hop-by-hop options. An attacker could exploit this vulnerability by sending a malicious IPv6 packet to or through the affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition on an affected device.

A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition, or to execute arbitrary code on an affected device. The vulnerability is due to improper validation of packet data. An attacker could exploit this vulnerability by sending a crafted Smart Install message to an affected device on TCP port 4786. A successful exploit could allow the attacker to cause a buffer overflow on the affected device, which could have the following impacts: Triggering a reload of the device, Allowing the attacker to execute arbitrary code on the device, Causing an indefinite loop on the affected device that triggers a watchdog crash. Cisco Bug IDs: CSCvg76186.

A vulnerability in the IPv6 traffic processing of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an unexpected restart of the netstack process on an affected device. The vulnerability is due to improper validation of IPv6 traffic sent through an affected device. An attacker could exploit this vulnerability by sending a malformed IPv6 packet through an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition while the netstack process restarts. A sustained attack could lead to a reboot of the device.

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol component of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper input validation on fields within CAPWAP Discovery Request packets by the affected device. An attacker could exploit this vulnerability by sending malicious CAPWAP Discovery Request packets to the Cisco WLC Software. A successful exploit could allow the attacker to cause the Cisco WLC Software to disconnect associated access points (APs). While the APs disconnect and reconnect, service will be unavailable for a brief period of time, resulting in a DoS condition.

A vulnerability in the Border Gateway Protocol (BGP) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to the device unexpectedly reloading. The vulnerability is due to incomplete input validation of the BGP update messages. An attacker could exploit this vulnerability by sending a crafted BGP update message to the targeted device. An exploit could allow the attacker to cause the switch to reload unexpectedly. The Cisco implementation of the BGP protocol only accepts incoming BGP traffic from explicitly defined peers. To exploit this vulnerability, an attacker must be able to send the malicious packets over a TCP connection that appears to come from a trusted BGP peer or inject malformed messages into the victim's BGP network. This would require obtaining information about the BGP peers in the affected system's trusted network. The vulnerability may be triggered when the router receives a malformed BGP message from a peer on an existing BGP session. At least one BGP neighbor session must be established for a router to be vulnerable. This vulnerability affects Nexus 2000 Series Switches, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 3600 Platform Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCve79599, CSCve87784, CSCve91371, CSCve91387.