The cat6000-dot1x component in Cisco IOS 12.2 before 12.2(33)SXI7 does not properly handle (1) a loop between a dot1x enabled port and an open-authentication dot1x enabled port and (2) a loop between a dot1x enabled port and a non-dot1x port, which allows remote attackers to cause a denial of service (traffic storm) via unspecified vectors that trigger many Spanning Tree Protocol (STP) Bridge Protocol Data Unit (BPDU) frames, aka Bug ID CSCtq36327.

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 TFTP Server 1.1 allows remote attackers to cause a denial of service (daemon crash) via a crafted (1) read (aka RRQ) or (2) write (aka WRQ) request, or other TFTP packet. NOTE: some of these details are obtained from third party information.

The web-based management interface on Cisco Small Business 220 devices with firmware before 1.0.1.1 allows remote attackers to cause a denial of service (interface outage) via a crafted HTTP request, aka Bug ID CSCuz76238.

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.

The HTTPS Proxy feature in Cisco AsyncOS before 8.5.3-051 and 9.x before 9.0.0-485 on Web Security Appliance (WSA) devices allows remote attackers to cause a denial of service (service outage) by leveraging certain intranet connectivity and sending a malformed HTTPS request, aka Bug ID CSCuu24840.

Cisco TelePresence Video Communications Server (VCS) X8.x before X8.7.2 allows remote attackers to cause a denial of service (service disruption) via a crafted URI in a SIP header, aka Bug ID CSCuy43258.

Cisco Prime Network Analysis Module (NAM) before 6.2(1-b) miscalculates IPv6 payload lengths, which allows remote attackers to cause a denial of service (mond process crash and monitoring outage) via crafted IPv6 packets, aka Bug ID CSCuy37324.

Cisco IOS XR through 5.3.2 mishandles Local Packet Transport Services (LPTS) flow-base entries, which allows remote attackers to cause a denial of service (session drop) by making many connection attempts to open TCP ports, aka Bug ID CSCux95576.

Cisco IOS XR 4.2.3, 4.3.0, 4.3.4, and 5.3.1 on ASR 9000 devices allows remote attackers to cause a denial of service (CRC and symbol errors, and interface flap) via crafted bit patterns in packets, aka Bug ID CSCuv78548.

A vulnerability in the web-based management interface of Cisco Integrated Management Controller (IMC) Software could allow an unauthenticated, remote attacker to cause the web-based management interface to unexpectedly restart. The vulnerability is due to insufficient input validation on the web-based management interface. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to cause the interface to restart, resulting in a denial of service (DoS) condition.

A vulnerability in the Shell Access Filter feature of Cisco Firepower Management Center (FMC), when used in conjunction with remote authentication, could allow an unauthenticated, remote attacker to cause high disk utilization, resulting in a denial of service (DoS) condition. The vulnerability occurs because the configuration of the Shell Access Filter, when used with a specific type of remote authentication, can cause a system file to have unbounded writes. An attacker could exploit this vulnerability by sending a steady stream of remote authentication requests to the appliance when the specific configuration is applied. Successful exploitation could allow the attacker to increase the size of a system log file so that it consumes most of the disk space. The lack of available disk space could lead to a DoS condition in which the device functions could operate abnormally, making the device unstable.

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

The mobility extension on Cisco Unified IP 9900 phones with firmware 9.4(.1) and earlier allows remote attackers to cause a denial of service (logoff) via crafted packets, aka Bug ID CSCuq12139.

The SMB module in Cisco Wide Area Application Services (WAAS) 6.0(1) allows remote attackers to cause a denial of service (module reload) via an invalid field in a Negotiate Protocol request, aka Bug ID CSCuo75645.

tacacsd in Cisco IOS XR 5.1 and earlier allows remote attackers to cause a denial of service (process reload) via a malformed TACACS+ packet, aka Bug ID CSCum00468.

Cisco Wide Area Application Services (WAAS) 5.3(.5a) and earlier, when SharePoint acceleration is enabled, does not properly parse SharePoint responses, which allows remote attackers to cause a denial of service (application-optimization handler reload) via a crafted SharePoint application, aka Bug ID CSCue47674.

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 SSH module in the Integrated Management Controller (IMC) before 2.3.1 in Cisco Unified Computing System on E-Series blade servers allows remote attackers to cause a denial of service (IMC hang) via a crafted SSH packet, aka Bug ID CSCuo69206.

Cisco IOS 15.2(4)M4 on Cisco Unified Border Element (CUBE) devices allows remote attackers to cause a denial of service (input-queue consumption and traffic-processing outage) via crafted RTCP packets, aka Bug ID CSCuj72215.

The DHCPv6 server module in Cisco CNS Network Registrar 7.1 allows remote attackers to cause a denial of service (daemon reload) via a malformed DHCPv6 packet, aka Bug ID CSCuo07437.

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.

Memory leak in the GUI in the Impact server in Cisco Hosted Collaboration Solution (HCS) allows remote attackers to cause a denial of service (memory consumption) via unspecified vectors, aka Bug ID CSCub58999.

The Java-based software in Cisco Hosted Collaboration Solution (HCS) allows remote attackers to cause a denial of service (closing of TCP ports) via unspecified vectors, aka Bug IDs CSCug77633, CSCug77667, CSCug78266, CSCug82795, and CSCuh58643.

A vulnerability in the netconf interface of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on affected system. The vulnerability is due to improper handling of malformed requests processed by the netconf process. An attacker could exploit this vulnerability by sending malicious requests to the affected software. An exploit could allow the attacker to cause the targeted process to restart, resulting in a DoS condition on the affected system. Cisco Bug IDs: CSCvg95792.

A vulnerability in the reassembly logic for fragmented IPv4 packets of Cisco StarOS running on virtual platforms could allow an unauthenticated, remote attacker to trigger a reload of the npusim process, resulting in a denial of service (DoS) condition. There are four instances of the npusim process running per Service Function (SF) instance, each handling a subset of all traffic flowing across the device. It is possible to trigger a reload of all four instances of the npusim process around the same time. The vulnerability is due to improper handling of fragmented IPv4 packets containing options. An attacker could exploit this vulnerability by sending a malicious IPv4 packet across an affected device. An exploit could allow the attacker to trigger a restart of the npusim process, which will result in all traffic queued toward this instance of the npusim process to be dropped while the process is restarting. The npusim process typically restarts within less than a second. This vulnerability affects: Cisco Virtualized Packet Core-Single Instance (VPC-SI), Cisco Virtualized Packet Core-Distributed Instance (VPC-DI), Cisco Ultra Packet Core (UPC). Cisco Bug IDs: CSCvh29613.

A vulnerability in the peer-to-peer message processing functionality of Cisco Packet Data Network Gateway could allow an unauthenticated, remote attacker to cause the Session Manager (SESSMGR) process on an affected device to restart, resulting in a denial of service (DoS) condition. The vulnerability is due to incorrect validation of peer-to-peer packet headers. An attacker could exploit this vulnerability by sending a crafted peer-to-peer packet through an affected device. A successful exploit could allow the attacker to cause the SESSMGR process on the affected device to restart unexpectedly, which could briefly impact traffic while the SESSMGR process restarts and result in a DoS condition. Cisco Bug IDs: CSCvg88786.

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 Session Initiation Protocol (SIP) call-handling functionality of Cisco IP Phone 7800 Series phones and Cisco IP Phone 8800 Series phones could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected phone. The vulnerability is due to incomplete input validation of SIP Session Description Protocol (SDP) parameters by the SDP parser of an affected phone. An attacker could exploit this vulnerability by sending a malformed SIP packet to an affected phone. A successful exploit could allow the attacker to cause all active phone calls on the affected phone to be dropped while the SIP process on the phone unexpectedly restarts, resulting in a DoS condition. Cisco Bug IDs: CSCvf40066.

A vulnerability in the TCP throttling process of Cisco Prime Network could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient rate limiting protection for TCP listening ports. An attacker could exploit this vulnerability by sending the affected device a high rate of TCP SYN packets to the local IP address of the targeted application. A successful exploit could allow the attacker to cause the device to consume a high amount of memory and become slow, or to stop accepting new TCP connections to the application. Cisco Bug IDs: CSCvg48152.

A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. It is also possible on certain software releases that the ASA will not reload, but an attacker could view sensitive system information without authentication by using directory traversal techniques. The vulnerability is due to lack of proper input validation of the HTTP URL. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. An exploit could allow the attacker to cause a DoS condition or unauthenticated disclosure of information. This vulnerability applies to IPv4 and IPv6 HTTP traffic. This vulnerability affects Cisco ASA Software and Cisco Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 1000V Cloud Firewall, 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 Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4100 Series Security Appliance, Firepower 9300 ASA Security Module, FTD Virtual (FTDv). Cisco Bug IDs: CSCvi16029.

A vulnerability in TCP connection management in Cisco Prime Access Registrar could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition when the application unexpectedly restarts. The vulnerability is due to incorrect handling of incoming TCP SYN packets to specific listening ports. The improper handling of the TCP SYN packets could cause a system file description to be allocated and not freed. An attacker could exploit this vulnerability by sending a crafted stream of TCP SYN packets to the application. A successful exploit could allow the attacker to cause the application to eventually restart if a file description cannot be obtained.

A vulnerability in the IPsec Manager of Cisco StarOS for Cisco Aggregation Services Router (ASR) 5000 Series Routers and Virtualized Packet Core (VPC) System Software could allow an unauthenticated, remote attacker to terminate all active IPsec VPN tunnels and prevent new tunnels from being established, resulting in a denial of service (DoS) condition. The vulnerability is due to improper processing of corrupted Internet Key Exchange Version 2 (IKEv2) messages. An attacker could exploit this vulnerability by sending crafted IKEv2 messages toward an affected router. A successful exploit could allow the attacker to cause the ipsecmgr service to reload. A reload of this service could cause all IPsec VPN tunnels to be terminated and prevent new tunnels from being established until the service has restarted, resulting in a DoS condition. This vulnerability affects the following Cisco products when they are running Cisco StarOS: Cisco Aggregation Services Router (ASR) 5000 Series Routers, Virtualized Packet Core (VPC) System Software. Cisco Bug IDs: CSCve29605.

A vulnerability in the Precision Time Protocol (PTP) subsystem of Cisco IOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition of the Precision Time Protocol. The vulnerability is due to insufficient processing of PTP packets. An attacker could exploit this vulnerability by sending a custom PTP packet to, or through, an affected device. A successful exploit could allow the attacker to cause a DoS condition for the PTP subsystem, resulting in time synchronization issues across the network.

A vulnerability in the Real-Time Transport Protocol (RTP) bitstream processing of the Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient input validation of incoming RTP bitstreams. An attacker could exploit this vulnerability by sending a crafted RTP bitstream to an affected Cisco Meeting Server. A successful exploit could allow the attacker to deny audio and video services by causing media process crashes resulting in a DoS condition on the affected product. This vulnerability affects Cisco Meeting Server deployments that are running Cisco Meeting Server Software Releases 2.0, 2.1, 2.2, and 2.3. Cisco Bug IDs: CSCve79693, CSCvf91393, CSCvg64656, CSCvh30725, CSCvi86363.

A vulnerability in the TCP stack of Cisco SocialMiner could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition in the notification system. The vulnerability is due to faulty handling of new TCP connections to the affected application. An attacker could exploit this vulnerability by sending a malicious TCP packet to the vulnerable service. An exploit could allow the attacker to create a DoS condition by interrupting certain phone services. A manual restart of the service may be required to restore full functionalities. Cisco Bug IDs: CSCvh48368.

A vulnerability in management interface access control list (ACL) configuration of Cisco NX-OS System Software could allow an unauthenticated, remote attacker to bypass configured ACLs on the management interface. This could allow traffic to be forwarded to the NX-OS CPU for processing, leading to high CPU utilization and a denial of service (DoS) condition. The vulnerability is due to a bad code fix in the 7.3.2 code train that could allow traffic to the management interface to be misclassified and not match the proper configured ACLs. An attacker could exploit this vulnerability by sending crafted traffic to the management interface. An exploit could allow the attacker to bypass the configured management interface ACLs and impact the CPU of the targeted device, resulting in a DoS condition. This vulnerability affects the following Cisco products running Cisco NX-OS System Software: Multilayer Director Switches, Nexus 2000 Series Switches, Nexus 3000 Series Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Switches in standalone NX-OS mode. Cisco Bug IDs: CSCvf31132.

The tNetTaskLimit process on the Transport Node Controller (TNC) on Cisco ONS 15454 devices with software 9.6 and earlier does not properly prioritize health pings, which allows remote attackers to cause a denial of service (watchdog timeout and TNC reset) via a flood of network traffic, aka Bug ID CSCud97155.

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.

A vulnerability in the XCP Router service of the Cisco Unified Communications Manager IM & Presence Service (CUCM IM&P) and the Cisco TelePresence Video Communication Server (VCS) and Expressway could allow an unauthenticated, remote attacker to cause a temporary service outage for all IM&P users, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a malicious IPv4 or IPv6 packet to an affected device on TCP port 7400. An exploit could allow the attacker to overread a buffer, resulting in a crash and restart of the XCP Router service. Cisco Bug IDs: CSCvg97663, CSCvi55947.

A vulnerability in the Session Initiation Protocol (SIP) ingress packet processing of Cisco Unified IP Phone software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to a lack of flow-control mechanisms in the software. An attacker could exploit this vulnerability by sending high volumes of SIP INVITE traffic to the targeted device. Successful exploitation could allow the attacker to cause a disruption of services on the targeted IP phone. Cisco Bug IDs: CSCve10064, CSCve14617, CSCve14638, CSCve14683, CSCve20812, CSCve20926, CSCve20945.

A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause one of the detection engine processes to run out of memory and thus slow down traffic processing. The vulnerability is due to improper handling of traffic when the Secure Sockets Layer (SSL) inspection policy is enabled. An attacker could exploit this vulnerability by sending malicious traffic through an affected device. An exploit could allow the attacker to increase the resource consumption of a single instance of the Snort detection engine on an affected device. This will lead to performance degradation and eventually the restart of the affected Snort process. Cisco Bug IDs: CSCvi09219, CSCvi29845.

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.

A vulnerability in the Interactive Voice Response (IVR) management connection interface for Cisco Unified Customer Voice Portal (CVP) could allow an unauthenticated, remote attacker to cause the IVR connection to disconnect, creating a system-wide denial of service (DoS) condition. The vulnerability is due to improper handling of a TCP connection request when the IVR connection is already established. An attacker could exploit this vulnerability by initiating a crafted connection to the IP address of the targeted CVP device. An exploit could allow the attacker to disconnect the IVR to CVP connection, creating a DoS condition that prevents the CVP from accepting new, incoming calls while the IVR automatically attempts to re-establish the connection to the CVP. This vulnerability affects Cisco Unified Customer Voice Portal (CVP) Software Release 11.5(1). Cisco Bug IDs: CSCve70560.

Cisco Secure Access Control System (ACS) does not properly implement an incoming-packet firewall rule, which allows remote attackers to cause a denial of service (process crash) via a flood of crafted packets, aka Bug ID CSCui51521.

Buffer overflow in the web-application interface on Cisco 9900 IP phones allows remote attackers to cause a denial of service (webapp interface outage) via long values in unspecified fields, aka Bug ID CSCuh10343.

Cisco Secure Access Control System (ACS) does not properly handle requests to read from the TACACS+ socket, which allows remote attackers to cause a denial of service (process crash) via malformed TCP packets, aka Bug ID CSCuh12488.

Cisco Common Services, as used in Cisco Prime LAN Management Solution (LMS), Cisco Security Manager, Cisco Unified Service Monitor, and Cisco Unified Operations Manager, does not properly interact with the ActiveMQ component, which allows remote attackers to cause a denial of service (memory consumption) via simultaneous TCP sessions, aka Bug IDs CSCuh54766, CSCuh01267, CSCuh95976, and CSCuh95969.

A vulnerability in Address Resolution Protocol (ARP) management of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to prevent an affected device from resolving ARP entries for legitimate hosts on the connected subnets. This vulnerability exists because ARP entries are mismanaged. An attacker could exploit this vulnerability by continuously sending traffic that results in incomplete ARP entries. A successful exploit could allow the attacker to cause ARP requests on the device to be unsuccessful for legitimate hosts, resulting in a denial of service (DoS) condition.

A vulnerability in Ethernet over GRE (EoGRE) packet processing of Cisco IOS XE Wireless Controller Software for the Cisco Catalyst 9800 Family Wireless Controller, Embedded Wireless Controller, and Embedded Wireless on Catalyst 9000 Series Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper processing of malformed EoGRE packets. An attacker could exploit this vulnerability by sending malicious packets to the affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.