A vulnerability in the Network Time Protocol (NTP) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to excessive use of system resources when the affected device is logging a drop action for received MODE_PRIVATE (Mode 7) NTP packets. An attacker could exploit this vulnerability by flooding the device with a steady stream of Mode 7 NTP packets. A successful exploit could allow the attacker to cause high CPU and memory usage on the affected device, which could cause internal system processes to restart or cause the affected device to unexpectedly reload. Note: The NTP feature is enabled by default.

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.

Cisco 12000 with IOS 12.0 and line cards based on Engine 2 does not handle the "fragment" keyword in a compiled ACL (Turbo ACL) for packets that are sent to the router, which allows remote attackers to cause a denial of service via a flood of fragments.

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.

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

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.

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 passthrough FTP feature on Cisco Web Security Appliance (WSA) devices with software 8.0.7-142 and 8.5.1-021 allows remote attackers to cause a denial of service (CPU consumption) via FTP sessions in which the control connection is ended after data transfer, aka Bug ID CSCut94150.

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.

The RADIUS functionality on Cisco Wireless LAN Controller (WLC) devices with software 7.0(250.0) and 7.0(252.0) allows remote attackers to disconnect arbitrary sessions via crafted Disconnect-Request UDP packets, aka Bug ID CSCuw29419.

Cisco Prime Infrastructure 2.2 allows remote attackers to cause a denial of service (daemon hang) by sending many SSL renegotiation requests, aka Bug ID CSCuv56830.

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 CSCun36525.

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.

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.

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.

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 IPv4 implementation on Cisco ASR 1000 devices with software 15.5(3)S allows remote attackers to cause a denial of service (ESP QFP CPU consumption) by triggering packet fragmentation and reassembly, aka Bug ID CSCuv71273.

A vulnerability in the Ident protocol handler of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability exists because the affected software incorrectly handles memory structures, leading to a NULL pointer dereference. An attacker could exploit this vulnerability by opening a TCP connection to specific ports and sending traffic over that connection. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition.

A vulnerability in the web-based management interface of Cisco Integrated Management Controller (IMC) Supervisor, Cisco UCS Director, and Cisco UCS Director Express for Big Data could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to a missing authentication check in an API call. An attacker who can send a request to an affected system could cause all currently authenticated users to be logged off. Repeated exploitation could cause the inability to maintain a session in the web-based management portal.

A vulnerability in the ingress packet processing function of Cisco IOS Software for Cisco Catalyst 4000 Series Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper resource allocation when processing TCP packets directed to the device on specific Cisco Catalyst 4000 Series Switches. An attacker could exploit this vulnerability by sending crafted TCP streams to an affected device. A successful exploit could cause the affected device to run out of buffer resources, impairing operations of control plane and management plane protocols, resulting in a DoS condition. This vulnerability can be triggered only by traffic that is destined to an affected device and cannot be exploited using traffic that transits an affected device.

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 IOS XR 5.2.1 allows remote attackers to cause a denial of service (ipv6_io service reload) via a malformed IPv6 packet, aka Bug ID CSCuq95565.

The SSL VPN implementation in Cisco Adaptive Security Appliance (ASA) Software 9.3(.2) and earlier does not properly allocate memory blocks during HTTP packet handling, which allows remote attackers to cause a denial of service (memory consumption) via crafted packets, aka Bug ID CSCuq68888.

Nexus Data Broker (NDB) on Cisco Nexus 3000 devices with software 6.0(2)A6(1) allows remote attackers to cause a denial of service (Java process restart) via crafted connections to the Java application, aka Bug ID CSCut87006.

The packet-reassembly implementation in Cisco IOS XE 3.13S and earlier allows remote attackers to cause a denial of service (CPU consumption or packet loss) via fragmented (1) IPv4 or (2) IPv6 packets that trigger ATTN-3-SYNC_TIMEOUT errors after reassembly failures, aka Bug ID CSCuo37957.

The authentication-manager process in the web framework in Cisco Intrusion Prevention System (IPS) 7.0(8)E4 and earlier in Cisco Intrusion Detection System (IDS) does not properly manage user tokens, which allows remote attackers to cause a denial of service (temporary MainApp hang) via a crafted connection request to the management interface, aka Bug ID CSCuq39550.

Cisco Unified Communications Domain Manager Platform Software 4.4(.3) and earlier allows remote attackers to cause a denial of service (CPU consumption) by sending crafted TCP packets quickly, aka Bug ID CSCuo42063.

Cisco IOS 15.4(3)S0b on ASR901 devices makes incorrect decisions to use the CPU for IPv4 packet processing, which allows remote attackers to cause a denial of service (BGP neighbor flapping) by sending many crafted IPv4 packets, aka Bug ID CSCuo29736.

Cisco ONS 15454 controller cards with software 10.0 and earlier allow remote attackers to cause a denial of service (card reload) via a crafted HTTP URI, aka Bug ID CSCun06870.

Memory leak in the SIP inspection engine in Cisco Adaptive Security Appliance (ASA) Software allows remote attackers to cause a denial of service (memory consumption and instability) via crafted SIP packets, aka Bug ID CSCuf67469.

Cisco ONS 15454 controller cards with software 9.6 and earlier allow remote attackers to cause a denial of service (flash write outage) via a TCP FIN attack that triggers file-descriptor exhaustion, aka Bug ID CSCug97315.

The REST API in Cisco Access Control Server (ACS) 5.5(0.46.2) allows remote attackers to cause a denial of service (API outage) by sending many requests, aka Bug ID CSCut62022.

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.

telnetd in Cisco IOS XR 5.0.1 on Network Convergence System 6000 devices allows remote attackers to cause a denial of service (device reload) via a malformed TELNET packet, aka Bug ID CSCuq31566.

A vulnerability in Cisco 900 Series Aggregation Services Router (ASR) software could allow an unauthenticated, remote attacker to cause a partial denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient handling of certain broadcast packets ingress to the device. An attacker could exploit this vulnerability by sending large streams of broadcast packets to an affected device. If successful, an exploit could allow an attacker to impact services running on the device, resulting in a partial DoS condition.

Cisco Headend System Release allows remote attackers to cause a denial of service (DHCP and TFTP outage) via a flood of crafted UDP traffic, aka Bug ID CSCus04097.

A vulnerability in the DHCP module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability is due to incorrect processing of certain DHCP packets. An attacker could exploit this vulnerability by sending a crafted DHCP packet to the affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

Multiple vulnerabilities in the Zone-Based Firewall feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload or stop forwarding traffic through the firewall. The vulnerabilities are due to incomplete handling of Layer 4 packets through the device. An attacker could exploit these vulnerabilities by sending a certain sequence of traffic patterns through the device. A successful exploit could allow the attacker to cause the device to reload or stop forwarding traffic through the firewall, resulting in a denial of service. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to restart unexpectedly. The vulnerability is due to a lack of sufficient memory management protections under heavy SNMP polling loads. An attacker could exploit this vulnerability by sending a high rate of SNMP requests to the SNMP daemon through the management interface on an affected device. A successful exploit could allow the attacker to cause the SNMP daemon process to consume a large amount of system memory over time, which could then lead to an unexpected device restart, causing a denial of service (DoS) condition. This vulnerability affects all versions of SNMP.

The IKE implementation in Cisco IOS 15.4(1)T and earlier and IOS XE allows remote attackers to cause a denial of service (security-association drop) via crafted Main Mode packets, aka Bug ID CSCun31021.

A vulnerability in the SSH service of the Cisco StarOS operating system could allow an unauthenticated, remote attacker to cause an affected device to stop processing traffic, resulting in a denial of service (DoS) condition. The vulnerability is due to a logic error that may occur under specific traffic conditions. An attacker could exploit this vulnerability by sending a series of crafted packets to an affected device. A successful exploit could allow the attacker to prevent the targeted service from receiving any traffic, which would lead to a DoS condition on the affected device.

Multiple vulnerabilities in the ingress packet processing function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

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 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 a crash and reload of an affected device, resulting in a denial of service (DoS) condition.The vulnerability is due to a crash that occurs during a hash lookup for a SIP pinhole connection. An attacker could exploit this vulnerability by sending crafted SIP traffic through an affected device. A successful exploit could allow the attacker to cause a crash and reload of the affected device.

A vulnerability in the Cisco IOx Application Framework of Cisco 809 Industrial Integrated Services Routers (Industrial ISRs), Cisco 829 Industrial ISRs, Cisco CGR 1000 Compute Module, and Cisco IC3000 Industrial Compute Gateway could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient error handling during packet processing. An attacker could exploit this vulnerability by sending a high and sustained rate of crafted TCP traffic to the IOx web server on an affected device. A successful exploit could allow the attacker to cause the IOx web server to stop processing requests, resulting in a DoS condition.

A vulnerability in the Multi-Pod or Multi-Site network configurations for Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, remote attacker to unexpectedly restart the device, resulting in a denial of service (DoS) condition. This vulnerability exists because TCP traffic sent to a specific port on an affected device is not properly sanitized. An attacker could exploit this vulnerability by sending crafted TCP data to a specific port that is listening on a public-facing IP address for the Multi-Pod or Multi-Site configuration. A successful exploit could allow the attacker to cause the device to restart unexpectedly, resulting in a 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.

Cisco ONS 15454 System Software 10.30 and 10.301 allows remote attackers to cause a denial of service (tNetTask CPU consumption or card reset) via a flood of (1) IP or (2) Ethernet traffic, aka Bug ID CSCus57263.