The auth-proxy functionality in Cisco Firewall Services Module (FWSM) software 3.1 and 3.2 before 3.2(20.1), 4.0 before 4.0(15.2), and 4.1 before 4.1(5.1) allows remote attackers to cause a denial of service (device reload) via a crafted URL, aka Bug ID CSCtg02624.

Cisco Firewall Services Module (aka FWSM) 3.1 before 3.1(21), 3.2 before 3.2(22), 4.0 before 4.0(16), and 4.1 before 4.1(7), when certain authentication configurations are used, allows remote attackers to cause a denial of service (module crash) by making many authentication requests for network access, aka Bug ID CSCtn15697.

Unspecified vulnerability in the SSH server in (1) Cisco Service Control Engine (SCE) 3.0.x before 3.0.7 and 3.1.x before 3.1.0, and (2) Icon Labs Iconfidant SSH before 2.3.8, allows remote attackers to cause a denial of service (management interface outage) via SSH traffic that occurs during management operations and triggers "illegal I/O operations," aka Bug ID CSCsh49563.

The SIP Proxy (SIPD) service in Cisco Unified Presence before 6.0(3) allows remote attackers to cause a denial of service (core dump and service interruption) via a TCP port scan, aka Bug ID CSCsj64533.

Cisco Unified IP Phone 7940, 7940G, 7960, and 7960G running SCCP firmware allows remote attackers to cause a denial of service (reboot) via a long ICMP echo request (ping) packet.

The SSH server in (1) Cisco Service Control Engine (SCE) before 3.1.6, and (2) Icon Labs Iconfidant SSH before 2.3.8, allows remote attackers to cause a denial of service (device restart or daemon outage) via a high rate of login attempts, aka Bug ID CSCsi68582.

Multiple unspecified vulnerabilities in the SIP inspection functionality in Cisco PIX and Adaptive Security Appliance (ASA) 5500 devices 7.0 before 7.0(7)16, 7.1 before 7.1(2)71, 7.2 before 7.2(4)7, 8.0 before 8.0(3)20, and 8.1 before 8.1(1)8 allow remote attackers to cause a denial of service (device reload) via unknown vectors, aka Bug IDs CSCsq07867, CSCsq57091, CSCsk60581, and CSCsq39315.

The Message Transfer Service (MTS) in Cisco NX-OS before 6.2(7) on MDS 9000 devices and 6.0 before 6.0(2) on Nexus 7000 devices allows remote attackers to cause a denial of service (NULL pointer dereference and kernel panic) via a large volume of crafted traffic, aka Bug ID CSCtw98915.

The Cisco Unified IP Phone 8945 with software 9.3(2) allows remote attackers to cause a denial of service (device hang) via a malformed PNG file, aka Bug ID CSCud04270.

Cisco NX-OS on Nexus 5500 devices 4.x and 5.x before 5.0(3)N2(2), Nexus 3000 devices 5.x before 5.0(3)U3(2), and Unified Computing System (UCS) 6200 devices before 2.0(1w) allows remote attackers to cause a denial of service (device reload) by sending a jumbo packet to the management interface, aka Bug IDs CSCtx17544, CSCts10593, and CSCtx95389.

Cisco Intrusion Prevention System (IPS) Software in ASA 5500-X IPS-SSP software modules before 7.1(7)sp1E4 allows remote attackers to cause a denial of service (Analysis Engine process hang or device reload) via fragmented (1) IPv4 or (2) IPv6 packets, aka Bug ID CSCue51272.

The Wireless Intrusion Prevention System (wIPS) component on Cisco Wireless LAN Controller (WLC) devices with software 7.0 before 7.0.235.0, 7.1 and 7.2 before 7.2.110.0, and 7.3 before 7.3.101.0 allows remote attackers to cause a denial of service (device reload) via crafted IP packets, aka Bug ID CSCtx80743.

The General Responder implementation in the IP Service Level Agreement (SLA) feature in Cisco IOS 15.2 and IOS XE 3.1.xS through 3.4.xS before 3.4.5S and 3.5.xS through 3.7.xS before 3.7.2S allows remote attackers to cause a denial of service (device reload) via crafted (1) IPv4 or (2) IPv6 IP SLA packets on UDP port 1167, aka Bug ID CSCuc72594.

Cisco Adaptive Security Appliances (ASA) devices with software 9.0 before 9.0(1.2) allow remote attackers to cause a denial of service (device reload) via a crafted field in a DNS message, aka Bug ID CSCuc80080.

Cisco Adaptive Security Appliances (ASA) devices with software 7.x before 7.2(5.10), 8.0 before 8.0(5.28), 8.1 and 8.2 before 8.2(5.35), 8.3 before 8.3(2.34), 8.4 before 8.4(4.11), 8.6 before 8.6(1.10), and 8.7 before 8.7(1.3), and Cisco Firewall Services Module (FWSM) software 3.1 and 3.2 before 3.2(24.1) and 4.0 and 4.1 before 4.1(11.1), allow remote attackers to cause a denial of service (device reload) via a crafted IKEv1 message, aka Bug IDs CSCub85692 and CSCud20267.

Cisco Unified CallManager (CUCM) 5.0 before 5.0(4a)SU1 and Cisco Unified Presence Server (CUPS) 1.0 before 1.0(3) allow remote attackers to cause a denial of service (loss of voice services) via a flood of ICMP echo requests, aka bug ID CSCsf12698.

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.

Linux kernel versions 4.9+ can be forced to make very expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for every incoming packet which can lead to a denial of service.

Cisco IOS XE 3.4 before 3.4.4S, 3.5, and 3.6 on 1000 series Aggregation Services Routers (ASR) does not properly implement the Cisco Multicast Leaf Recycle Elimination (MLRE) feature, which allows remote attackers to cause a denial of service (card reload) via fragmented IPv6 multicast packets, aka Bug ID CSCtz97563.

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.

Cisco AS5350 IOS 12.2(11)T with access control lists (ACLs) applied and possibly with ssh running allows remote attackers to cause a denial of service (crash) via a port scan, possibly due to an ssh bug. NOTE: this issue could not be reproduced by the vendor

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.

Cisco IOS allows remote attackers to cause a denial of service (crash) via a crafted IPv6 Type 0 Routing header.

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.

Cisco Wireless LAN Controller (WLC) devices with software 7.0 before 7.0.220.0, 7.1 before 7.1.91.0, and 7.2 before 7.2.103.0 allow remote attackers to cause a denial of service (Access Point reload) via crafted SIP packets, aka Bug ID CSCts87659.

Cisco Firewall Services Module (FWSM) 3.x before 3.1(3.11), when the HTTPS server is enabled, allows remote attackers to cause a denial of service (device reboot) via certain HTTPS traffic.

The IP stack in Cisco Intrusion Prevention System (IPS) Software in ASA 5500-X IPS-SSP software and hardware modules before 7.1(5)E4, IPS 4500 sensors before 7.1(6)E4, and IPS 4300 sensors before 7.1(5)E4 allows remote attackers to cause a denial of service (MainApp process hang) via malformed IPv4 packets, aka Bug ID CSCtx18596.

The management API in the XML API management service in the Manager component in Cisco Unified Computing System (UCS) 1.x before 1.2(1b) allows remote attackers to cause a denial of service (service outage) via a malformed request, aka Bug ID CSCtg48206.

Cisco IOS after 12.3(14)T, 12.3(8)YC1, 12.3(8)YG, and 12.4, with voice support and without Session Initiated Protocol (SIP) configured, allows remote attackers to cause a denial of service (crash) by sending a crafted packet to port 5060/UDP.

The data-link switching (DLSw) component in Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service (device restart or memory consumption) via crafted (1) UDP port 2067 or (2) IP protocol 91 packets.

A vulnerability in the cryptographic hardware accelerator driver of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a temporary denial of service (DoS) condition. The vulnerability exists because the affected devices have a limited amount of Direct Memory Access (DMA) memory and the affected software improperly handles resources in low-memory conditions. An attacker could exploit this vulnerability by sending a sustained, high rate of malicious traffic to an affected device to exhaust memory on the device. A successful exploit could allow the attacker to exhaust DMA memory on the affected device, which could cause the device to reload and result in a temporary DoS condition.

A vulnerability in the Session Initiation Protocol (SIP) inspection engine of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload or trigger high CPU, resulting in a denial of service (DoS) condition. The vulnerability is due to improper handling of SIP traffic. An attacker could exploit this vulnerability by sending SIP requests designed to specifically trigger this issue at a high rate across an affected device. Software updates that address this vulnerability are not yet available.

A vulnerability in the email message filtering feature of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to cause the CPU utilization to increase to 100 percent, causing a denial of service (DoS) condition on an affected device. The vulnerability is due to improper filtering of email messages that contain references to whitelisted URLs. An attacker could exploit this vulnerability by sending a malicious email message that contains a large number of whitelisted URLs. A successful exploit could allow the attacker to cause a sustained DoS condition that could force the affected device to stop scanning and forwarding email messages.

Memory leak in Cisco IOS 12.2, 12.4, 15.0, and 15.1, when Zone-Based Policy Firewall SIP application layer gateway inspection is enabled, allows remote attackers to cause a denial of service (memory consumption or device reload) via malformed SIP messages, aka Bug ID CSCtl99174.

A vulnerability in the IPv6 subsystem of Cisco IOS XR Software Release 5.3.4 for the Cisco Aggregation Services Router (ASR) 9000 Series could allow an unauthenticated, remote attacker to trigger a reload of one or more Trident-based line cards, resulting in a denial of service (DoS) condition. The vulnerability is due to incorrect handling of IPv6 packets with a fragment header extension. An attacker could exploit this vulnerability by sending IPv6 packets designed to trigger the issue either to or through the Trident-based line card. A successful exploit could allow the attacker to trigger a reload of Trident-based line cards, resulting in a DoS during the period of time the line card takes to restart. This vulnerability affects Cisco Aggregation Services Router (ASR) 9000 Series when the following conditions are met: The router is running Cisco IOS XR Software Release 5.3.4, and the router has installed Trident-based line cards that have IPv6 configured. A software maintenance upgrade (SMU) has been made available that addresses this vulnerability. The fix has also been incorporated into service pack 7 for Cisco IOS XR Software Release 5.3.4. Cisco Bug IDs: CSCvg46800.

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 Bidirectional Forwarding Detection (BFD) offload implementation of Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches could allow an unauthenticated, remote attacker to cause a crash of the iosd process, causing a denial of service (DoS) condition. The vulnerability is due to insufficient error handling when the BFD header in a BFD packet is incomplete. An attacker could exploit this vulnerability by sending a crafted BFD message to or across an affected switch. A successful exploit could allow the attacker to trigger a reload of the system. This vulnerability affects Catalyst 4500 Supervisor Engine 6-E (K5), Catalyst 4500 Supervisor Engine 6L-E (K10), Catalyst 4500 Supervisor Engine 7-E (K10), Catalyst 4500 Supervisor Engine 7L-E (K10), Catalyst 4500E Supervisor Engine 8-E (K10), Catalyst 4500E Supervisor Engine 8L-E (K10), Catalyst 4500E Supervisor Engine 9-E (K10), Catalyst 4500-X Series Switches (K10), Catalyst 4900M Switch (K5), Catalyst 4948E Ethernet Switch (K5). Cisco Bug IDs: CSCvc40729.

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.

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 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 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 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 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 implementation of Internet Key Exchange Version 1 (IKEv1) functionality in Cisco IOS Software and Cisco IOS XE Software 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 improper validation of specific IKEv1 packets. An attacker could exploit this vulnerability by sending crafted IKEv1 packets to an affected device during an IKE negotiation. A successful exploit could allow the attacker to cause an affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCuj73916.

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.

Cisco Unified Presence Server (CUPS) 8.6, 9.0, and 9.1 before 9.1.1 allows remote attackers to cause a denial of service (CPU consumption) via crafted packets to the SIP TCP port, aka Bug ID CSCua89930.