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.

The Cisco Application Control Engine (ACE) module 3.0 for Cisco Catalyst switches and Cisco routers does not properly monitor Load Balancer (LB) queues, which allows remote attackers to cause a denial of service (incorrect memory access and module reboot) via application traffic, aka Bug ID CSCtw70879.

The Cisco VC220 and VC240 cameras allow remote attackers to cause a denial of service (WebUI outage) via crafted packets, aka Bug IDs CSCtf73188, CSCtf88059, CSCtf87951, CSCtf87908, and CSCtf88019.

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 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 REST interface in Cisco Spark 2015-06 allows remote attackers to cause a denial of service (resource outage) by accessing an administrative page, aka Bug ID CSCuv84125.

Unspecified vulnerability in Cisco ASA 5500 Series Adaptive Security Appliance 7.0 before 7.0(8.10), 7.2 before 7.2(4.45), 8.0 before 8.0(5.1), 8.1 before 8.1(2.37), and 8.2 before 8.2(1.15); and Cisco PIX 500 Series Security Appliance; allows remote attackers to cause a denial of service (active IPsec tunnel loss and prevention of new tunnels) via a malformed IKE message through an existing tunnel to UDP port 4500, aka Bug ID CSCtc47782.

IP Security VPN Services Module (VPNSM) in Cisco Catalyst 6500 Series Switch and the Cisco 7600 Series Internet Routers running IOS before 12.2(17b)SXA, before 12.2(17d)SXB, or before 12.2(14)SY03 could allow remote attackers to cause a denial of service (device crash and reload) via a malformed Internet Key Exchange (IKE) packet.

Cisco Internetwork Operating System (IOS) 12.0S through 12.3T attempts to process SNMP solicited operations on improper ports (UDP 162 and a randomly chosen UDP port), which allows remote attackers to cause a denial of service (device reload and memory corruption).

The SIP implementation in Cisco IOS 15.5(3)M on Cisco Unified Border Element (CUBE) devices allows remote attackers to cause a denial of service via crafted SIP messages, aka Bug ID CSCuv79202.

Cisco Web Security Appliance (WSA) 8.0.6-078 and 8.0.6-115 allows remote attackers to cause a denial of service (service outage) via a flood of TCP traffic that leads to DNS resolution delays, aka Bug IDs CSCur32005 and CSCur07907.

The DHCPv6 server in Cisco IOS on ASR 9000 devices with software 5.2.0 Base allows remote attackers to cause a denial of service (process reset) via crafted packets, aka Bug ID CSCun72171.

The Web Management GUI on Cisco Wireless LAN Controller (WLC) devices with software 7.4(140.0) and 8.0(120.0) allows remote attackers to cause a denial of service (client disconnection) via unspecified vectors, aka Bug ID CSCuw10610.

Cisco ASR 5000 devices with software 16.0(900) allow remote attackers to cause a denial of service (telnetd process restart) via a TELNET connection, aka Bug ID CSCuv25815.

Cisco CatOS 5.x before 5.5(20) through 8.x before 8.2(2) and 8.3(2)GLX, as used in Catalyst switches, allows remote attackers to cause a denial of service (system crash and reload) by sending invalid packets instead of the final ACK portion of the three-way handshake to the (1) Telnet, (2) HTTP, or (3) SSH services, aka "TCP-ACK DoS attack."

Cisco IOS XR 4.2.0, 4.3.0, 5.0.0, 5.1.0, 5.2.0, 5.2.2, 5.2.4, 5.3.0, and 5.3.2 does not properly restrict the number of Path Computation Elements (PCEs) for OSPF LSA opaque area updates, which allows remote attackers to cause a denial of service (device reload) via a crafted update, aka Bug ID CSCuw83486.

Cisco ASR 5500 System Architecture Evolution (SAE) Gateway devices with software 19.1.0.61559 and 19.2.0 allow remote attackers to cause a denial of service (BGP process restart) via a crafted header in a BGP packet, aka Bug ID CSCuw65781.

Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allow remote attackers to cause a denial of service (ASDM syslog outage) via a long URL, aka Bug IDs CSCsm11264 and CSCtb92911.

Memory leak in the gk_circuit_info_do_in_acf function in the H.323 implementation in Cisco IOS before 15.0(1)XA allows remote attackers to cause a denial of service (memory consumption) via a large number of calls over a long duration, as demonstrated by InterZone Clear Token (IZCT) test traffic, aka Bug ID CSCsz72535.

A vulnerability in the Protection Against Distributed Denial of Service Attacks feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct denial of service (DoS) attacks to or through the affected device. This vulnerability is due to incorrect programming of the half-opened connections limit, TCP SYN flood limit, or TCP SYN cookie features when the features are configured in vulnerable releases of Cisco IOS XE Software. An attacker could exploit this vulnerability by attempting to flood traffic to or through the affected device. A successful exploit could allow the attacker to initiate a DoS attack to or through an affected device.

The web server for Cisco Aironet AP1x00 Series Wireless devices running certain versions of IOS 12.2 allow remote attackers to cause a denial of service (reload) via a malformed URL.

Cisco VPN 3000 series concentrators and Cisco VPN 3002 Hardware Client 2.x.x through 3.6.7A allow remote attackers to cause a denial of service (slowdown and possibly reload) via a flood of malformed ICMP packets.

A vulnerability in the email scanning algorithm of Cisco AsyncOS software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to perform a denial of service (DoS) attack against an affected device. This vulnerability is due to insufficient input validation of incoming emails. An attacker could exploit this vulnerability by sending a crafted email through Cisco ESA. A successful exploit could allow the attacker to exhaust all the available CPU resources on an affected device for an extended period of time, preventing other emails from being processed and resulting in a DoS condition.

Cisco IOS 11.1 through 12.2, when HSRP support is not enabled, allows remote attackers to cause a denial of service (CPU consumption) via randomly sized UDP packets to the Hot Standby Routing Protocol (HSRP) port 1985.

A vulnerability in the DHCP version 4 (DHCPv4) server feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to trigger a crash of the dhcpd process, resulting in a denial of service (DoS) condition. This vulnerability exists because certain DHCPv4 messages are improperly validated when they are processed by an affected device. An attacker could exploit this vulnerability by sending a malformed DHCPv4 message to an affected device. A successful exploit could allow the attacker to cause a NULL pointer dereference, resulting in a crash of the dhcpd process. While the dhcpd process is restarting, which may take up to approximately two minutes, DHCPv4 server services are unavailable on the affected device. This could temporarily prevent network access to clients that join the network during that time period. Note: Only the dhcpd process crashes and eventually restarts automatically. The router does not reload.

Cisco 2611 router running IOS 12.1(6.5), possibly an interim release, allows remote attackers to cause a denial of service via port scans such as (1) scanning all ports on a single host and (2) scanning a network of hosts for a single open port through the router. NOTE: the vendor could not reproduce this issue, saying that the original reporter was using an interim release of the software.

A vulnerability in the TCP Normalizer of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software operating in transparent mode could allow an unauthenticated, remote attacker to poison MAC address tables, resulting in a denial of service (DoS) vulnerability. This vulnerability is due to incorrect handling of certain TCP segments when the affected device is operating in transparent mode. An attacker could exploit this vulnerability by sending a crafted TCP segment through an affected device. A successful exploit could allow the attacker to poison the MAC address tables in adjacent devices, resulting in network disruption.

Cisco SN 5420 Storage Router 1.1(5) and earlier allows remote attackers to cause a denial of service (halt) via a fragmented packet to the Gigabit interface.

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.

Cisco Virtual Private Network (VPN) Client software 2.x.x and 3.x before 3.0.5 allows remote attackers to cause a denial of service (crash) via TCP packets with source and destination ports of 137 (NETBIOS).

The web management interface for Cisco Content Service Switch (CSS) 11000 switches allows remote attackers to cause a denial of service (soft reset) via (1) an HTTPS POST request, or (2) malformed XML data.

A vulnerability in IPv6 packet fragment reassembly of StarOS for Cisco Aggregation Services Router (ASR) 5000 Series Switch could allow an unauthenticated, remote attacker to cause an unexpected reload of the Network Processing Unit (NPU) process. More Information: CSCva84552. Known Affected Releases: 20.0.0 21.0.0 21.0.M0.64702. Known Fixed Releases: 21.0.0 21.0.0.65256 21.0.M0.64970 21.0.V0.65150 21.1.A0.64973 21.1.PP0.65270 21.1.R0.65130 21.1.R0.65135 21.1.VC0.65203.

Cisco ONS15454 optical transport platform running ONS 3.1.0 to 3.2.0 allows remote attackers to cause a denial of service (reset) by sending IP packets with non-zero Type of Service (TOS) bits to the Timing Control Card (TCC) LAN interface.

A vulnerability in the detection engine parsing of Pragmatic General Multicast (PGM) protocol packets for Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to the Snort process unexpectedly restarting. The vulnerability is due to improper input validation of the fields in the PGM protocol packet. An attacker could exploit this vulnerability by sending a crafted PGM packet to the detection engine on the targeted device. An exploit could allow the attacker to cause a DoS condition if the Snort process restarts and traffic inspection is bypassed or traffic is dropped. This vulnerability affects Cisco Firepower System Software that has one or more file action policies configured and is running on any of the following Cisco products: Adaptive Security Appliance (ASA) 5500-X Series 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 Security Appliances; FirePOWER 7000 Series Appliances; FirePOWER 8000 Series Appliances; Firepower 9300 Series Security Appliances; FirePOWER Threat Defense for Integrated Services Routers (ISRs); Industrial Security Appliance 3000; Sourcefire 3D System Appliances; Virtual Next-Generation Intrusion Prevention System (NGIPSv) for VMware. Fixed versions: 5.4.0.10 5.4.1.9 6.0.1.3 6.1.0 6.2.0. Cisco Bug IDs: CSCuz00876.

Memory leak in the Call Telephony Integration (CTI) Framework authentication for Cisco CallManager 3.0 and 3.1 before 3.1(3) allows remote attackers to cause a denial of service (crash and reload) via a series of authentication failures, e.g. via incorrect passwords.

Cisco VPN 3000 Concentrator before 2.5.2(F), with encryption enabled, allows remote attackers to cause a denial of service (reload) via a Windows-based PPTP client with the "No Encryption" option set.

Cisco VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.3, allows remote attackers to cause a denial of service (crash) via a long (1) username or (2) password to the HTML login interface.

A vulnerability in Advanced Malware Protection (AMP) for Cisco Email Security Appliances (ESA) and Web Security Appliances (WSA) could allow an unauthenticated, remote attacker to cause a partial denial of service (DoS) condition due to the AMP process unexpectedly restarting. Affected Products: Cisco AsyncOS Software for Email Security Appliances (ESA) versions 9.5 and later up to the first fixed release, Cisco AsyncOS Software for Web Security Appliances (WSA) all versions prior to the first fixed release. More Information: CSCux56406, CSCux59928. Known Affected Releases: 9.6.0-051 9.7.0-125 8.8.0-085 9.5.0-444 WSA10.0.0-000. Known Fixed Releases: 9.7.1-066 WSA10.0.0-233.

Cisco AsyncOS through 9.5.0-444 on Web Security Appliance (WSA) devices allows remote attackers to cause a denial of service (link saturation) by making many HTTP requests for overlapping byte ranges simultaneously, aka Bug ID CSCuz27219.

Cisco routers and switches running IOS 12.0 through 12.2.1 allows a remote attacker to cause a denial of service via a flood of UDP packets.

Cisco 600 series routers running CBOS 2.0.1 through 2.4.2ap allows remote attackers to cause a denial of service via multiple connections to the router on the (1) HTTP or (2) telnet service, which causes the router to become unresponsive and stop forwarding packets.

Cisco 12000 with IOS 12.0 and line cards based on Engine 2 and earlier allows remote attackers to cause a denial of service (CPU consumption) by flooding the router with traffic that generates a large number of ICMP Unreachable replies.

Cisco Catalyst 6000, 5000, or 4000 switches allow remote attackers to cause a denial of service by connecting to the SSH service with a non-SSH client, which generates a protocol mismatch error.

Buffer overflow in Cisco TACACS+ tac_plus server allows remote attackers to cause a denial of service via a malformed packet with a long length field.

Attackers can crash a Cisco IOS router or device, provided they can get to an interactive prompt (such as a login). This applies to some IOS 9.x, 10.x, and 11.x releases.

Cisco IOS 12.0 and other versions can be crashed by malicious UDP packets to the syslog port.

A vulnerability in the Slowpath of StarOS for Cisco ASR 5500 Series routers with Data Processing Card 2 (DPC2) could allow an unauthenticated, remote attacker to cause a subset of the subscriber sessions to be disconnected, resulting in a partial denial of service (DoS) condition. This vulnerability affects Cisco ASR 5500 devices with Data Processing Card 2 (DPC2) running StarOS 18.0 or later. More Information: CSCvb12081. Known Affected Releases: 18.7.4 19.5.0 20.0.2.64048 20.2.3 21.0.0. Known Fixed Releases: 18.7.4 18.7.4.65030 18.8.M0.65044 19.5.0 19.5.0.65092 19.5.M0.65023 19.5.M0.65050 20.2.3 20.2.3.64982 20.2.3.65017 20.2.a4.65307 20.3.M0.64984 20.3.M0.65029 20.3.M0.65037 20.3.M0.65071 20.3.T0.64985 20.3.T0.65031 20.3.T0.65043 20.3.T0.65067 21.0.0 21.0.0.65256 21.0.M0.64922 21.0.M0.64983 21.0.M0.65140 21.0.V0.65150 21.1.A0.64932 21.1.A0.64987 21.1.A0.65145 21.1.PP0.65270 21.1.R0.65130 21.1.R0.65135 21.1.R0.65154 21.1.VC0.65203 21.2.A0.65147.

Cisco IOS 15.2S allows remote attackers to cause a denial of service (interface queue wedge) via malformed UDP traffic on port 465, aka Bug ID CSCts48300.

A vulnerability in local FTP to the Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause a partial denial of service (DoS) condition when the FTP application unexpectedly quits. More Information: CSCux68539. Known Affected Releases: 9.1.0-032 9.7.1-000. Known Fixed Releases: 9.1.1-038.

A vulnerability in HTTP URL parsing of Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) vulnerability due to the proxy process unexpectedly restarting. More Information: CSCvb04312. Known Affected Releases: 9.0.1-162 9.1.1-074. Known Fixed Releases: 10.1.0-129 9.1.2-010.