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.

A vulnerability in the UDP protocol implementation for Cisco IoT Field Network Director (IoT-FND) could allow an unauthenticated, remote attacker to exhaust system resources, resulting in a denial of service (DoS) condition. The vulnerability is due to improper resource management for UDP ingress packets. An attacker could exploit this vulnerability by sending a high rate of UDP packets to an affected system within a short period of time. A successful exploit could allow the attacker to exhaust available system resources, resulting in a DoS condition.

A vulnerability in the web interface of Cisco IoT Field Network Director could allow an unauthenticated, remote attacker to trigger high CPU usage, resulting in a denial of service (DoS) condition on an affected device. The vulnerability is due to improper handling of Transport Layer Security (TLS) renegotiation requests. An attacker could exploit this vulnerability by sending renegotiation requests at a high rate. A successful exploit could increase the resource usage on the system, eventually leading to a DoS condition.

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.

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 interactions between the DHCP and TFTP features for Cisco Small Business 300 Series (Sx300) Managed Switches could allow an unauthenticated, remote attacker to cause the device to become low on system memory, which in turn could lead to an unexpected reload of the device and result in a denial of service (DoS) condition on an affected device. The vulnerability is due to a failure to free system memory when an unexpected DHCP request is received. An attacker could exploit this vulnerability by sending a crafted DHCP packet to the targeted device. A successful exploit could allow the attacker to cause an unexpected reload of the device.

Multiple vulnerabilities in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to either immediately crash the Internet Group Management Protocol (IGMP) process or make it consume available memory and eventually crash. The memory consumption may negatively impact other processes that are running on the device. These vulnerabilities are due to the incorrect handling of IGMP packets. An attacker could exploit these vulnerabilities by sending crafted IGMP traffic to an affected device. A successful exploit could allow the attacker to immediately crash the IGMP process or cause memory exhaustion, resulting in other processes becoming unstable. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address these vulnerabilities.

A vulnerability in the HTTP server code of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the HTTP server to crash. The vulnerability is due to a logical error in the logging mechanism. An attacker could exploit this vulnerability by generating a high amount of long-lived connections to the HTTP service on the device. A successful exploit could allow the attacker to cause the HTTP server to crash.

A vulnerability in the Secure Login Enhancements capability of Cisco Nexus 1000V Switch for VMware vSphere could allow an unauthenticated, remote attacker to cause an affected Nexus 1000V Virtual Supervisor Module (VSM) to become inaccessible to users through the CLI. The vulnerability is due to improper resource allocation during failed CLI login attempts when login parameters that are part of the Secure Login Enhancements capability are configured on an affected device. An attacker could exploit this vulnerability by performing a high amount of login attempts against the affected device. A successful exploit could cause the affected device to become inaccessible to other users, resulting in a denial of service (DoS) condition requiring a manual power cycle of the VSM to recover.

A vulnerability in the Local Packet Transport Services (LPTS) ingress frame-processing functionality of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause one of the LPTS processes on an affected system to restart unexpectedly, resulting in a brief denial of service (DoS) condition. The vulnerability is due to incomplete LPTS frame validation by the affected software. An attacker could exploit this vulnerability by sending crafted XML requests to the management interface of an affected system. A successful exploit could allow the attacker to cause one of the LPTS processes on the affected system to restart unexpectedly, which would impact LPTS traffic and cause a brief DoS condition while the process restarts. Cisco Bug IDs: CSCvf76332.

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.

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.

Cisco IOS 15.0 through 15.5 and IOS XE 3.3 through 3.16 allow remote attackers to cause a denial of service (device reload) via a crafted DHCPv6 Relay message, aka Bug ID CSCus55821.

The web GUI on Cisco Small Business 500 devices 1.2.0.92 allows remote attackers to cause a denial of service via a crafted HTTP request, aka Bug ID CSCul65330.

Cisco Virtual Private Network (VPN) Client 3.5.4 and earlier allows remote attackers to cause a denial of service (CPU consumption) via a packet with a zero-length payload.

Buffer overflows in Cisco Virtual Private Network (VPN) Client 3.5.4 and earlier allows remote attackers to cause a denial of service via (1) an Internet Key Exchange (IKE) with a large Security Parameter Index (SPI) payload, or (2) an IKE packet with a large number of valid payloads.

Cisco AsyncOS 8.0 before 8.0.6-119 on Web Security Appliance (WSA) devices allows remote attackers to cause a denial of service (proxy-process hang) via a crafted HTTP POST request, aka Bug ID CSCuo12171.

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 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 IOS 12.2 and earlier running Cisco Discovery Protocol (CDP) allows remote attackers to cause a denial of service (memory consumption) via a flood of CDP neighbor announcements.

Cisco CBOS 2.3.8 and earlier allows remote attackers to cause a denial of service via an ICMP ECHO REQUEST (ping) with the IP Record Route option set.

Web-based configuration utility in Cisco 600 series routers running CBOS 2.0.1 through 2.4.2ap binds itself to port 80 even when web-based configuration services are disabled, which could leave the router open to attack.

Cisco Catalyst 5000 series switches 6.1(2) and earlier will forward an 802.1x frame on a Spanning Tree Protocol (STP) blocked port, which causes a network storm and a denial of service.

Cisco CBOS 2.3.8 and earlier allows remote attackers to cause a denial of service via a series of large ICMP ECHO REPLY (ping) packets, which cause it to enter ROMMON mode and stop forwarding packets.

Cisco VPN 3000 series concentrators before 2.5.2(F) allow remote attackers to cause a denial of service via an IP packet with an invalid IP option.

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.

Multiple Cisco networking products allow remote attackers to cause a denial of service on the local network via a series of ARP packets sent to the router's interface that contains a different MAC address for the router, which eventually causes the router to overwrite the MAC address in its ARP table.

Cisco IOS 12.1(2)T, 12.1(3)T allow remote attackers to cause a denial of service (reload) via a connection to TCP ports 3100-3999, 5100-5999, 7100-7999 and 10100-10999.

Cisco devices IOS 12.0 and earlier allow a remote attacker to cause a crash, or bad route updates, via malformed BGP updates with unrecognized transitive attribute.

Cisco 600 routers running CBOS 2.4.1 and earlier allow remote attackers to cause a denial of service via a large ICMP echo (ping) packet.

Cisco Gigabit Switch Routers (GSR) with Fast Ethernet / Gigabit Ethernet cards, from IOS versions 11.2(15)GS1A up to 11.2(19)GS0.2 and some versions of 12.0, do not properly handle line card failures, which allows remote attackers to bypass ACLs or force the interface to stop forwarding packets.

CBOS 2.4.1 and earlier in Cisco 600 routers allows remote attackers to cause a denial of service via a slow stream of TCP SYN packets.

The HTTP server in Cisco IOS 12.0 through 12.1 allows local users to cause a denial of service (crash and reload) via a URL containing a "?/" string.

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.

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.

The Cisco IronPort Email Security Appliance (ESA) allows remote attackers to cause a denial of service (CPU consumption) via long Subject headers in e-mail messages, aka Bug ID CSCzv93864.

Denial of service in Cisco IOS web server allows attackers to reboot the router using a long URL.

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

Denial of service in Cisco routers running NAT via a PORT command from an FTP client to a Telnet port.

Vulnerability in Cisco 7xx series routers allows a remote attacker to cause a system reload via a TCP connection to the router's TELNET port.

Cisco WebEx Meetings Server 2.6 allows remote attackers to cause a denial of service (CPU consumption) by repeatedly accessing the account-validation component of an unspecified service, aka Bug ID CSCuy92704.

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.

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.

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

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 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.

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.

A vulnerability in the cache server within Cisco Videoscape Distribution Suite (VDS) for Television 3.2(5)ES1 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted appliance. The vulnerability is due to excessive mapped connections exhausting the allotted resources within the system. An attacker could exploit this vulnerability by sending large amounts of inbound traffic to a device with the intention of overloading certain resources. A successful exploit could cause the device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvc39260.

Cisco IP Phone 8800 devices with software 11.0(1) allow remote attackers to cause a denial of service (memory corruption) via a crafted HTTP request, aka Bug ID CSCuz03038.