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.

A vulnerability in the Cisco TrustSec (CTS) Protected Access Credential (PAC) provisioning module of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of attributes in RADIUS messages. An attacker could exploit this vulnerability by sending a malicious RADIUS message to an affected device while the device is in a specific state.

A vulnerability in the Raw Socket Transport feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper parsing of Raw Socket Transport payloads. An attacker could exploit this vulnerability by establishing a TCP session and then sending a malicious TCP segment via IPv4 to an affected device. This cannot be exploited via IPv6, as the Raw Socket Transport feature does not support IPv6 as a network layer protocol.

Cisco IOS XE 2.x before 2.4.3 and 2.5.x before 2.5.1 on ASR 1000 devices allows remote attackers to cause a denial of service (Embedded Services Processor crash) via a crafted series of fragmented (1) IPv4 or (2) IPv6 packets, aka Bug ID CSCtd72617.

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 RADIUS Change of Authorization (CoA) code of Cisco TrustSec, a feature within Cisco IOS XE Software, could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper handling of a malformed packet. An attacker could exploit this vulnerability by sending a malformed packet to an affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

Cisco Videoscape Policy Resource Manager (PRM) 3.5.4 allows remote attackers to cause a denial of service (CPU and memory consumption, and TCP service outage) via (1) a SYN flood or (2) another type of TCP traffic flood, aka Bug IDs CSCuu35104 and CSCuu35128.

Multiple vulnerabilities in the EnergyWise module of Cisco IOS (12.2 and 15.0 through 15.6) and Cisco IOS XE (3.2 through 3.18) could allow an unauthenticated, remote attacker to cause a buffer overflow condition or a reload of an affected device, leading to a denial of service (DoS) condition. These vulnerabilities are due to improper parsing of crafted EnergyWise packets destined to an affected device. An attacker could exploit these vulnerabilities by sending crafted EnergyWise packets to be processed by an affected device. An exploit could allow the attacker to cause a buffer overflow condition or a reload of the affected device, leading to a DoS condition. Cisco IOS Software and Cisco IOS XE Software support EnergyWise for IPv4 communication. Only IPv4 packets destined to a device configured as an EnergyWise domain member can trigger these vulnerabilities. IPv6 packets cannot be used to trigger these vulnerabilities. Cisco Bug ID CSCuu76493.

A vulnerability in the Event Management Service daemon (emsd) of Cisco IOS XR routers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability is due to improper handling of gRPC requests. An attacker could exploit this vulnerability by repeatedly sending unauthenticated gRPC requests to the affected device. A successful exploit could allow the attacker to crash the device in such a manner that manual intervention is required to recover. This vulnerability affects all Cisco IOS XR platforms that are running release 6.1.1 of Cisco IOS XR Software when the gRPC service is enabled on the device. The gRPC service is not enabled by default. Cisco Bug IDs: CSCvb14441.

Memory leak in Cisco Headend System Release allows remote attackers to cause a denial of service (memory consumption) via unspecified vectors, aka Bug ID CSCus91838.

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.

Memory leak in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing Engine (PRE) module on UBR devices allows remote attackers to cause a denial of service (memory consumption) by triggering an error during CPE negotiation, aka Bug ID CSCug00885.

A vulnerability in the Network Address Translation (NAT) Session Initiation Protocol (SIP) Application Layer Gateway (ALG) of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper processing of transient SIP packets on which NAT is performed on an affected device. An attacker could exploit this vulnerability by using UDP port 5060 to send crafted SIP packets through an affected device that is performing NAT for SIP packets. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition.

A vulnerability in the WebVPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause increased CPU utilization on an affected device. The vulnerability is due to excessive processing load for a specific WebVPN HTTP page request. An attacker could exploit this vulnerability by sending multiple WebVPN HTTP page load requests for a specific URL. A successful exploit could allow the attacker to increase CPU load on the device, resulting in a denial of service (DoS) condition, which could cause traffic to be delayed through the device.

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.

Cisco IOS 12.4 allows remote attackers to cause a denial of service (device crash) via a normal, properly formed SSL packet that occurs during termination of an SSL session.

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.

The Zone-Based Firewall implementation in Cisco IOS 15.4(2)T3 and earlier allows remote attackers to cause a denial of service (device reload) via crafted network traffic that triggers incorrect kernel-timer handling, aka Bug ID CSCuh25672.

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.

A vulnerability in Unified Threat Defense (UTD) in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper validation of IPv6 packets through the UTD feature. An attacker could exploit this vulnerability by sending IPv6 traffic through an affected device that is configured with UTD. A successful exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition.

A vulnerability in the filesystem resource management code of Cisco IOS XE Software could allow an unauthenticated, remote attacker to exhaust filesystem resources on an affected device and cause a denial of service (DoS) condition. The vulnerability is due to ineffective management of the underlying filesystem resources. An attacker could exploit this vulnerability by performing specific actions that result in messages being sent to specific operating system log files. A successful exploit could allow the attacker to exhaust available filesystem space on an affected device. This could cause the device to crash and reload, resulting in a DoS condition for clients whose network traffic is transiting the device. Upon reload of the device, the impacted filesystem space is cleared, and the device will return to normal operation. However, continued exploitation of this vulnerability could cause subsequent forced crashes and reloads, which could lead to an extended DoS condition.

A vulnerability in the FTP application layer gateway (ALG) functionality used by Network Address Translation (NAT), NAT IPv6 to IPv4 (NAT64), and the Zone-Based Policy Firewall (ZBFW) in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to a buffer overflow that occurs when an affected device inspects certain FTP traffic. An attacker could exploit this vulnerability by performing a specific FTP transfer through the device. A successful exploit could allow the attacker to cause the device to reload.

Cisco IP Phone 7861, when firmware from Cisco Unified Communications Manager 10.3(1) is used, allows remote attackers to cause a denial of service via crafted packets, aka Bug ID CSCus81800.

A vulnerability in Cisco Aironet Access Point (AP) Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper handling of clients that are trying to connect to the AP. An attacker could exploit this vulnerability by sending authentication requests from multiple clients to an affected device. A successful exploit could allow the attacker to cause the affected device to reload.

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.

A vulnerability in the SIP inspection process 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 watchdog timeout and crash during the cleanup of threads that are associated with a SIP connection that is being deleted from the connection list. An attacker could exploit this vulnerability by sending a high rate of crafted SIP traffic through an affected device. A successful exploit could allow the attacker to cause a watchdog timeout and crash, resulting in a crash and reload of the affected device.

Cisco IOS XR 4.0.1 through 4.2.0 for CRS-3 Carrier Routing System allows remote attackers to cause a denial of service (NPU ASIC scan and line-card reload) via crafted IPv6 extension headers, aka Bug ID CSCtx03546.

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition of an affected device. The vulnerability is due to insufficient input validation during CAPWAP packet processing. An attacker could exploit this vulnerability by sending a crafted CAPWAP packet to an affected device, resulting in a buffer over-read. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition on the affected device.

Multiple vulnerabilities in the Media Gateway Control Protocol (MGCP) inspection feature of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerabilities are due to inefficient memory management. An attacker could exploit these vulnerabilities by sending crafted MGCP packets through an affected device. An exploit could allow the attacker to cause memory exhaustion resulting in a restart of an affected device, causing a DoS condition for traffic traversing the device.

A vulnerability in the web interface of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. The vulnerability is due to a lack of proper input validation of HTTP requests. 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. Note: This vulnerability applies to IP Version 4 (IPv4) and IP Version 6 (IPv6) HTTP traffic.

A vulnerability in the ICMP ingress packet processing of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 4110 appliances could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incomplete input validation upon receiving ICMP packets. An attacker could exploit this vulnerability by sending a high number of crafted ICMP or ICMPv6 packets to an affected device. A successful exploit could allow the attacker to cause a memory exhaustion condition that may result in an unexpected reload. No manual intervention is needed to recover the device after the reload.

A vulnerability in the locally significant certificate (LSC) provisioning feature of Cisco Catalyst 9800 Series Wireless Controllers that are running Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a memory leak that could lead to a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain public key infrastructure (PKI) packets. An attacker could exploit this vulnerability by sending crafted Secure Sockets Layer (SSL) packets to an affected device. A successful exploit could cause an affected device to continuously consume memory, which could result in a memory allocation failure that leads to a crash and causes a DoS condition.

A vulnerability in the Common Open Policy Service (COPS) engine of Cisco IOS XE Software on Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to crash a device. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending a malformed COPS message to the device. A successful exploit could allow the attacker to crash the device.

A vulnerability in the web UI of Cisco Small Business 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 validation of requests sent to the web interface. An attacker could exploit this vulnerability by sending a malicious request to the web interface of an affected device. A successful exploit could allow the attacker to cause an unexpected reload of the device, resulting in a DoS condition. This vulnerability affects firmware releases prior than 1.3.7.18

Multiple vulnerabilities in the implementation of the Common Industrial Protocol (CIP) feature of 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 vulnerabilities are due to insufficient input processing of CIP traffic. An attacker could exploit these vulnerabilities by sending crafted CIP traffic to be processed by an affected device. A successful exploit could allow the attacker to cause the 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 large number of TCP packets to a specific port on an affected device. A successful exploit could allow the attacker to exhaust system memory, which could cause the device to reload unexpectedly. No manual intervention is needed to recover the device after it has reloaded.

A vulnerability in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to exhaust process memory of an affected device. The vulnerability is due to insufficient queue management for Internet Group Management Protocol (IGMP) packets. An attacker could exploit this vulnerability by sending crafted IGMP traffic to an affected device. A successful exploit could allow the attacker to cause memory exhaustion, resulting in instability of other processes. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address this vulnerability.

A vulnerability in Cisco Aironet Access Points (APs) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) on an affected device. The vulnerability is due to improper resource management while processing specific packets. An attacker could exploit this vulnerability by sending a series of crafted UDP packets to a specific port on an affected device. A successful exploit could either allow the attacker to tear down the connection between the AP and the wireless LAN controller, resulting in the affected device not being able to process client traffic, or cause the vulnerable device to reload, triggering a DoS condition. After the attack, the affected device should automatically recover its normal functions without manual intervention.

A vulnerability in the packet processing of Cisco IOS XE Software for Cisco 4461 Integrated Services Routers 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 incorrect processing of IPv4 or IPv6 traffic to or through an affected device. An attacker could exploit this vulnerability by sending IP traffic to or through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

A vulnerability in the DHCP message handler of Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to cause the supervisor to crash, which could result in a denial of service (DoS) condition. The vulnerability is due to insufficient error handling when DHCP version 4 (DHCPv4) messages are parsed. An attacker could exploit this vulnerability by sending a malicious DHCPv4 message to or through a WAN interface of an affected device. A successful exploit could allow the attacker to cause a reload of the affected device. Note: On Cisco cBR-8 Converged Broadband Routers, all of the following are considered WAN interfaces: 10 Gbps Ethernet interfaces 100 Gbps Ethernet interfaces Port channel interfaces that include multiple 10 and/or 100 Gbps Ethernet interfaces

A vulnerability in the Session Initiation Protocol (SIP) of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incorrect handling of incoming SIP traffic. An attacker could exploit this vulnerability by sending a series of SIP packets to an affected device. A successful exploit could allow the attacker to exhaust memory on an affected device, causing it to crash and leading to a DoS condition.

Cisco NX-OS 4.0 through 6.1 on Nexus 1000V 3000, 4000, 5000, 6000, and 7000 devices and Unified Computing System (UCS) platforms allows remote attackers to cause a denial of service (TCP stack reload) by sending crafted TCP packets to a device that has a TIME_WAIT TCP session, aka Bug ID CSCub70579.

A vulnerability in the TCP packet processing 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 an affected device. The vulnerability is due to a memory exhaustion condition. An attacker could exploit this vulnerability by sending a high rate of crafted TCP traffic through an affected device. A successful exploit could allow the attacker to exhaust device resources, resulting in a DoS condition for traffic transiting the affected device.

A vulnerability in the generic routing encapsulation (GRE) tunnel decapsulation feature 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 a memory handling error when GRE over IPv6 traffic is processed. An attacker could exploit this vulnerability by sending crafted GRE over IPv6 packets with either IPv4 or IPv6 payload through an affected device. A successful exploit could allow the attacker to cause the device to crash, resulting in a DoS condition.

The Autonomic Networking Infrastructure (ANI) implementation in Cisco IOS 12.2, 12.4, 15.0, 15.2, 15.3, and 15.4 and IOS XE 3.10.xS through 3.13.xS before 3.13.1S allows remote attackers to cause a denial of service (device reload) via spoofed AN messages, aka Bug ID CSCup62315.

Cisco IOS XE 2.x and 3.x before 3.9.0S, 3.10 before 3.10.0S, 3.11 before 3.11.0S, 3.12 before 3.12.0S, 3.13 before 3.13.0S, 3.14 before 3.14.0S, and 3.15 before 3.15.0S allows remote attackers to cause a denial of service (device reload) via crafted IPv6 packets, aka Bug ID CSCub68073.

A vulnerability in the TCP packet processing functionality of Cisco IP Phones could allow an unauthenticated, remote attacker to cause the phone to stop responding to incoming calls, drop connected calls, or unexpectedly reload. The vulnerability is due to insufficient TCP ingress packet rate limiting. An attacker could exploit this vulnerability by sending a high and sustained rate of crafted TCP traffic to the targeted device. A successful exploit could allow the attacker to impact operations of the phone or cause the phone to reload, leading to a denial of service (DoS) condition.

The Cisco Cius with software before 9.2(1) SR2 allows remote attackers to cause a denial of service (device crash or hang) via malformed network traffic, aka Bug ID CSCto71445.