A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to restart an instance of the Snort detection engine on an affected device, resulting in a brief denial of service (DoS) condition. The vulnerability is due to the incorrect handling of a Transport Layer Security (TLS) extension during TLS connection setup for the affected software. An attacker could exploit this vulnerability by sending a crafted TLS connection setup request to an affected device. A successful exploit could allow the attacker to cause the Snort detection engine on the affected device to restart, resulting in a DoS condition. Cisco Bug IDs: CSCvg97808.

Cisco IOS 11.x and 12.0 with ATM support allows attackers to cause a denial of service via the undocumented Interim Local Management Interface (ILMI) SNMP community string.

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.

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.

emWEB on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allows remote attackers to cause a denial of service (daemon crash) via a request for a document whose name contains space characters, aka Bug ID CSCsy08416.

Cisco PIX firewall and CBAC IP fragmentation attack results in a denial of service.

STCAPP (aka the SCCP telephony control application) on Cisco IOS before 15.0(1)XA1 does not properly handle multiple calls to a shared line, which allows remote attackers to cause a denial of service (port hang) by simultaneously ending two calls that were controlled by CallManager Express (CME), aka Bug ID CSCtd42552.

The packet-processing microcode in Cisco IOS 15.2(2)EA, 15.2(2)EA1, 15.2(2)EA2, and 15.2(4)EA on Industrial Ethernet 4000 devices and 15.2(2)EB and 15.2(2)EB1 on Industrial Ethernet 5000 devices allows remote attackers to cause a denial of service (packet data corruption) via crafted IPv4 ICMP packets, aka Bug ID CSCuy13431.

Cisco IOS XR 3.4.0 through 3.9.1, when BGP is enabled, does not properly handle unrecognized transitive attributes, which allows remote attackers to cause a denial of service (peering reset) via a crafted prefix announcement, as demonstrated in the wild in August 2010 with attribute type code 99, aka Bug ID CSCti62211.

Cisco Unified Personal Communicator 7.0 (1.13056) does not free allocated memory for received data and does not perform validation if memory allocation is successful, causing a remote denial of service condition.

The web-management GUI implementation on Cisco Small Business SG300 devices 1.4.1.x allows remote attackers to cause a denial of service (HTTPS outage) via crafted HTTPS requests, aka Bug ID CSCuw87174.

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.

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.

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.

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.

A vulnerability in the egress packet processing functionality of the Cisco StarOS operating system for Cisco Aggregation Services Router (ASR) 5700 Series devices and Virtualized Packet Core (VPC) System Software could allow an unauthenticated, remote attacker to cause an interface on the device to cease forwarding packets. The device may need to be manually reloaded to clear this Interface Forwarding Denial of Service condition. The vulnerability is due to the failure to properly check that the length of a packet to transmit does not exceed the maximum supported length of the network interface card (NIC). An attacker could exploit this vulnerability by sending a crafted IP packet or a series of crafted IP fragments through an interface on the targeted device. A successful exploit could allow the attacker to cause the network interface to cease forwarding packets. This vulnerability could be triggered by either IPv4 or IPv6 network traffic. This vulnerability affects the following Cisco products when they are running the StarOS operating system and a virtual interface card is installed on the device: Aggregation Services Router (ASR) 5700 Series, Virtualized Packet Core-Distributed Instance (VPC-DI) System Software, Virtualized Packet Core-Single Instance (VPC-SI) System Software. Cisco Bug IDs: CSCvf32385.

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 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.

Cisco IOS XR 5.1 and earlier allows remote attackers to cause a denial of service (process reload) via a malformed RSVP packet, aka Bug ID CSCuq12031.

A vulnerability in the Rate Limiting Network Address Translation (NAT) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause high CPU utilization in the Cisco QuantumFlow Processor of an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to mishandling of the rate limiting feature within the QuantumFlow Processor. An attacker could exploit this vulnerability by sending large amounts of traffic that would be subject to NAT and rate limiting through an affected device. A successful exploit could allow the attacker to cause the QuantumFlow Processor utilization to reach 100 percent on the affected device, resulting in a DoS condition.

A vulnerability in the RADIUS feature of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause the affected system to stop processing RADIUS packets. This vulnerability is due to improper handling of certain RADIUS requests. An attacker could exploit this vulnerability by attempting to authenticate to a network or a service where the access server is using Cisco ISE as the RADIUS server. A successful exploit could allow the attacker to cause Cisco ISE to stop processing RADIUS requests, causing authentication/authorization timeouts, which would then result in legitimate requests being denied access. Note: To recover the ability to process RADIUS packets, a manual restart of the affected Policy Service Node (PSN) is required. See the Details section for more information.

A vulnerability in the data plane microcode of Lightspeed-Plus line cards for Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause the line card to reset. This vulnerability is due to the incorrect handling of malformed packets that are received on the Lightspeed-Plus line cards. An attacker could exploit this vulnerability by sending a crafted IPv4 or IPv6 packet through an affected device. A successful exploit could allow the attacker to cause the Lightspeed-Plus line card to reset, resulting in a denial of service (DoS) condition for any traffic that traverses that line card.

Cisco Secure Access Control Server (ACS) 3.2, when configured as a Light Extensible Authentication Protocol (LEAP) RADIUS proxy, allows remote attackers to cause a denial of service (device crash) via certain LEAP authentication requests.

A vulnerability in the implementation of the Datagram TLS (DTLS) protocol in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause high CPU utilization, resulting in a denial of service (DoS) condition. This vulnerability is due to suboptimal processing that occurs when establishing a DTLS tunnel as part of an AnyConnect SSL VPN connection. An attacker could exploit this vulnerability by sending a steady stream of crafted DTLS traffic to an affected device. A successful exploit could allow the attacker to exhaust resources on the affected VPN headend device. This could cause existing DTLS tunnels to stop passing traffic and prevent new DTLS tunnels from establishing, resulting in a DoS condition. Note: When the attack traffic stops, the device recovers gracefully.

A vulnerability in the TCP/IP stack of Cisco Email Security Appliance (ESA), Cisco Web Security Appliance (WSA), and Cisco Secure Email and Web Manager, formerly Security Management Appliance, could allow an unauthenticated, remote attacker to crash the Simple Network Management Protocol (SNMP) service, resulting in a denial of service (DoS) condition. This vulnerability is due to an open port listener on TCP port 199. An attacker could exploit this vulnerability by connecting to TCP port 199. A successful exploit could allow the attacker to crash the SNMP service, resulting in a DoS condition.

A vulnerability in the local malware analysis process of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. This vulnerability is due to insufficient error handling in the local malware analysis process of an affected device. An attacker could exploit this vulnerability by sending a crafted file through the device. A successful exploit could allow the attacker to cause the local malware analysis process to crash, which could result in a DoS condition. Notes: Manual intervention may be required to recover from this situation. Malware cloud lookup and dynamic analysis will not be impacted.

A vulnerability in the gRPC code of Cisco IOS XR Software for Cisco Network Convergence System (NCS) 5500 Series Routers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition when the emsd service stops. The vulnerability is due to the software's inability to process HTTP/2 packets. An attacker could exploit this vulnerability by sending a malformed HTTP/2 frame to the affected device. A successful exploit could allow the attacker to create a DoS condition when the emsd service stops. Cisco Bug IDs: CSCvb99388.

A vulnerability in the General Packet Radio Service (GPRS) Tunneling Protocol ingress packet handler of Cisco ASR 5500 System Architecture Evolution (SAE) Gateways could allow an unauthenticated, remote attacker to cause a partial denial of service (DoS) condition on an affected device. The vulnerability is due to improper input validation of GPRS Tunneling Protocol packet headers. An attacker could exploit this vulnerability by sending a malformed GPRS Tunneling Protocol packet to an affected device. A successful exploit could allow the attacker to cause the GTPUMGR process on an affected device to restart unexpectedly, resulting in a partial DoS condition. If the GTPUMGR process restarts, there could be a brief impact on traffic passing through the device. Cisco Bug IDs: CSCve07119.

A vulnerability in the implementation of Session Initiation Protocol (SIP) functionality in Cisco Small Business SPA51x Series 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 the improper handling of SIP request messages by an affected device. An attacker could exploit this vulnerability by sending malformed 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. This vulnerability affects Cisco Small Business SPA51x Series IP Phones that are running Cisco SPA51x Firmware Release 7.6.2SR1 or earlier. Cisco Bug IDs: CSCvc63982.

A vulnerability in the TCP state machine of Cisco RF Gateway 1 devices could allow an unauthenticated, remote attacker to prevent an affected device from delivering switched digital video (SDV) or video on demand (VoD) streams, resulting in a denial of service (DoS) condition. The vulnerability is due to a processing error with TCP connections to the affected device. An attacker could exploit this vulnerability by establishing a large number of TCP connections to an affected device and not actively closing those TCP connections. A successful exploit could allow the attacker to prevent the affected device from delivering SDV or VoD streams to set-top boxes. Cisco Bug IDs: CSCvf19887.

A vulnerability in the HTTP web interface for Cisco Wide Area Application Services (WAAS) could allow an unauthenticated, remote attacker to cause an HTTP Application Optimization (AO) related process to restart, causing a partial denial of service (DoS) condition. The vulnerability is due to lack of input validation of user-supplied input parameters within an HTTP request. An attacker could exploit this vulnerability by sending a crafted HTTP request through the targeted device. An exploit could allow the attacker to cause a DoS condition due to a process unexpectedly restarting. The WAAS could drop traffic during the brief time the process is restarting. Cisco Bug IDs: CSCvc63048.

dnsserver in Cisco Application Control Engine Global Site Selector (GSS) before 3.0(1) allows remote attackers to cause a denial of service (daemon crash) via a series of crafted DNS requests, aka Bug ID CSCsj70093.

A vulnerability in the H.264 decoder function of Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a Cisco Meeting Server media process to restart unexpectedly when it receives an illegal H.264 frame. The vulnerability is triggered by an H.264 frame that has an invalid picture parameter set (PPS) value. An attacker could exploit this vulnerability by sending a malformed H.264 frame to the targeted device. An exploit could allow the attacker to cause a denial of service (DoS) condition because the media process could restart. The media session should be re-established within a few seconds, during which there could be a brief interruption in service. Cisco Bug IDs: CSCvg12559.

A vulnerability in Cisco WebEx Meetings Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient limitations on the number of connections that can be made to the affected software. An attacker could exploit this vulnerability by opening multiple connections to the server and exhausting server resources. A successful exploit could cause the server to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvf41006.

A vulnerability in the implementation of Session Initiation Protocol (SIP) functionality in Cisco Small Business SPA50x, SPA51x, and SPA52x Series 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 the improper handling of SIP request messages by an affected device. An attacker could exploit this vulnerability by using formatted specifiers in a SIP payload that is sent 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. This vulnerability affects Cisco Small Business SPA50x, SPA51x, and SPA52x Series IP Phones that are running firmware release 7.6.2SR1 or earlier. Cisco Bug IDs: CSCvc63986.

A vulnerability in the Web Admin Interface of Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient bound checks performed by the affected software. An attacker could exploit this vulnerability by sending a malicious HTTP packet to the affected system. A successful exploit could allow the attacker to cause a reload of the Web Admin Server. Cisco Bug IDs: CSCve89149.

A vulnerability in SSL traffic decryption for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause depletion of system memory, aka a Firepower Detection Engine SSL Decryption Memory Consumption Denial of Service vulnerability. If this memory leak persists over time, a denial of service (DoS) condition could develop because traffic can cease to be forwarded through the device. The vulnerability is due to an error in how the Firepower Detection Snort Engine handles SSL traffic decryption and notifications to and from the Adaptive Security Appliance (ASA) handler. An attacker could exploit this vulnerability by sending a steady stream of malicious Secure Sockets Layer (SSL) traffic through the device. An exploit could allow the attacker to cause a DoS condition when the device runs low on system memory. This vulnerability affects Cisco Firepower Threat Defense (FTD) Software Releases 6.0.1 and later, running on any of the following Cisco products: Adaptive Security Appliance (ASA) 5500-X Series Next-Generation Firewalls, Firepower 2100 Series Security Appliances, Firepower 4100 Series Security Appliances, Firepower 9300 Series Security Appliances. Cisco Bug IDs: CSCve02069.

Unspecified vulnerability in an unspecified Microsoft API, as used by Cisco Unity and possibly other products, allows remote attackers to cause a denial of service by sending crafted packets to dynamic UDP ports, related to a "processing error."

A vulnerability in the web-based management interface of Cisco AsyncOS for Cisco Email Security Appliance (ESA), Cisco Web Security Appliance (WSA), and Cisco Content Security Management Appliance (SMA) could allow an unauthenticated remote attacker to cause high CPU usage on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of specific HTTP request headers. An attacker could exploit this vulnerability by sending a malformed HTTP request to an affected device. A successful exploit could allow the attacker to trigger a prolonged status of high CPU utilization relative to the GUI process(es). Upon successful exploitation of this vulnerability, an affected device will still be operative, but its response time and overall performance may be degraded.

A vulnerability in the OSPF Version 2 (OSPFv2) implementation 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 denial of service (DoS) condition. The vulnerability is due to incomplete input validation when the affected software processes certain OSPFv2 packets with Link-Local Signaling (LLS) data. An attacker could exploit this vulnerability by sending a malformed OSPFv2 packet to an affected device. A successful exploit could allow the attacker to cause an affected device to reload, resulting in a DoS condition.

A vulnerability in the packet processing functionality of 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 inefficient memory management. An attacker could exploit this vulnerability by sending a high rate of IPv4 or IPv6 traffic through an affected device. This traffic would need to match a configured block action in an access control policy. An exploit could allow the attacker to cause a memory exhaustion condition on the affected device, which would result in a DoS for traffic transiting the device, as well as sluggish performance of the management interface. Once the flood is stopped, performance should return to previous states.

A vulnerability in the Cisco Unified Reporting upload tool accessed via the Cisco Unified Communications Manager could allow an unauthenticated, remote attacker to modify arbitrary files on the file system. More Information: CSCvb61698. Known Affected Releases: 11.5(1.11007.2). Known Fixed Releases: 12.0(0.98000.168) 12.0(0.98000.178) 12.0(0.98000.399) 12.0(0.98000.510) 12.0(0.98000.536) 12.0(0.98500.7).

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.

Cisco IOS XR 5.2.2 allows remote attackers to cause a denial of service (process restart) via a crafted OSPF Link State Advertisement (LSA) update, aka Bug ID CSCvb05643.

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.

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 Catalyst LAN switches running Catalyst 5000 supervisor software allows remote attackers to perform a denial of service by forcing the supervisor module to reload.

Buffer overflow in Cisco 7xx routers through the telnet service.

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 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.