A vulnerability in the Internet Key Exchange version 2 (IKEv2) function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to prevent an affected device from processing any control plane UDP packets.  This vulnerability is due to improper handling of malformed IKEv2 packets. An attacker could exploit this vulnerability by sending malformed IKEv2 packets to an affected device. A successful exploit could allow the attacker to prevent the affected device from processing any control plane UDP packets, resulting in a denial of service (DoS) condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

A vulnerability in the file descriptor handling of Cisco TelePresence Video Communication Server (VCS) Expressway could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to exhaustion of file descriptors while processing a high volume of traffic. An attacker could exploit this vulnerability by establishing a high number of concurrent TCP connections to the vulnerable system. An exploit could allow the attacker to cause a restart in a specific process, resulting in a temporary interruption of service. Cisco Bug IDs: CSCvh77056, CSCvh77058, CSCvh95264.

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 TCP throttling process for Cisco IoT Field Network Director (IoT-FND) could allow an unauthenticated, remote attacker to cause the system to consume additional memory, eventually forcing the device to restart, aka Memory Exhaustion. The vulnerability is due to insufficient rate-limiting protection. An attacker could exploit this vulnerability by sending a high rate of TCP packets to a specific group of open listening ports on a targeted device. An exploit could allow the attacker to cause the system to consume additional memory. If enough available memory is consumed, the system will restart, creating a temporary denial of service (DoS) condition. The DoS condition will end after the device has finished the restart process. This vulnerability affects the following Cisco products: Connected Grid Network Management System, if running a software release prior to IoT-FND Release 4.0; IoT Field Network Director, if running a software release prior to IoT-FND Release 4.0. Cisco Bug IDs: CSCvc77164.

A vulnerability in the TCP connection handling functionality of Cisco Remote Expert Manager Software 11.0.0 could allow an unauthenticated, remote attacker to disable TCP ports and cause a denial of service (DoS) condition on an affected system. The vulnerability is due to a lack of rate-limiting functionality in the TCP Listen application of the affected software. An attacker could exploit this vulnerability by sending a crafted TCP traffic stream in which specific types of TCP packets are flooded to an affected device, for example a TCP packet stream in which the TCP FIN bit is set in all the TCP packets. A successful exploit could allow the attacker to cause certain TCP listening ports on the affected system to stop accepting incoming connections for a period of time or until the affected device is restarted, resulting in a DoS condition. In addition, system resources, such as CPU and memory, could be exhausted during the attack. Cisco Bug IDs: CSCva29806.

Multiple Cisco products are affected by a vulnerability in the way the Snort detection engine processes ICMP traffic that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper memory resource management while the Snort detection engine is processing ICMP packets. An attacker could exploit this vulnerability by sending a series of ICMP packets through an affected device. A successful exploit could allow the attacker to exhaust resources on the affected device, causing the device to reload.

Multiple vulnerabilities in the Cisco ATA 190 Series Analog Telephone Adapter Software could allow an attacker to perform a command injection attack resulting in remote code execution or 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 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 a logging API in Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause the device to become unresponsive or trigger an unexpected reload. This vulnerability could also allow an attacker with valid user credentials, but not Administrator privileges, to view a system log file that they would not normally have access to. This vulnerability is due to a lack of rate-limiting of requests that are sent to a specific API that is related to an FMC log. An attacker could exploit this vulnerability by sending a high rate of HTTP requests to the API. A successful exploit could allow the attacker to cause a denial of service (DoS) condition due to the FMC CPU spiking to 100 percent utilization or to the device reloading. CPU utilization would return to normal if the attack traffic was stopped before an unexpected reload was triggered.

A vulnerability in the internal packet-processing functionality of Cisco Firepower Threat Defense (FTD) Software for the Cisco Firepower 2100 Series 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, which may prevent ingress buffers from being replenished 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 consume all input buffers, which are shared between all interfaces, leading to a queue wedge condition in all active interfaces. This situation would cause an affected device to stop processing any incoming traffic and result in a DoS condition until the device is reloaded manually.

Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 4.x, 5.x before 5.1(3g), 6.x before 6.1(4), 7.0 before 7.0(2a)su1, and 7.1 before 7.1(2a)su1 allows remote attackers to cause a denial of service (file-descriptor exhaustion and SIP outage) via a flood of TCP packets, aka Bug ID CSCsx23689.

A vulnerability in the network stack of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability is due to an issue with allocating and freeing memory buffers in the network stack. An attacker could exploit this vulnerability by sending crafted TCP streams to an affected device in a sustained way. A successful exploit could cause the network stack of an affected device to run out of available buffers, impairing operations of control plane and management plane protocols, resulting in a DoS condition. Note: 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. Nexus 1000V Switch for Microsoft Hyper-V is affected in versions prior to 5.2(1)SM3(2.1). Nexus 1000V Switch for VMware vSphere is affected in versions prior to 5.2(1)SV3(4.1a). Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(6) and 9.2(2). Nexus 3500 Platform Switches are affected in versions prior to 6.0(2)A8(11), 7.0(3)I7(6), and 9.2(2). Nexus 3600 Platform Switches are affected in versions prior to 7.0(3)F3(5) and 9.2(2). Nexus 5500, 5600, and 6000 Series Switches are affected in versions prior to 7.1(5)N1(1b) and 7.3(5)N1(1). Nexus 7000 and 7700 Series Switches are affected in versions prior to 6.2(22. Nexus 9500 R-Series Line Cards and Fabric Modules are affected in versions prior to 7.0(3)F3(5) and 9.2(2). UCS 6200 and 6300 Series Fabric Interconnect are affected in versions prior to 3.2(3j) and 4.0(2a). UCS 6400 Series Fabric Interconnect are affected in versions prior to 4.0(2a).

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 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 the External Border Gateway Protocol (eBGP) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because eBGP traffic is mapped to a shared hardware rate-limiter queue. An attacker could exploit this vulnerability by sending large amounts of network traffic with certain characteristics through an affected device. A successful exploit could allow the attacker to cause eBGP neighbor sessions to be dropped, leading to a DoS condition in the network.

A vulnerability in the processing of IP Service Level Agreement (SLA) packets by Cisco IOS Software and Cisco IOS XE software could allow an unauthenticated, remote attacker to cause an interface wedge and an eventual denial of service (DoS) condition on the affected device. The vulnerability is due to improper socket resources handling in the IP SLA responder application code. An attacker could exploit this vulnerability by sending crafted IP SLA packets to an affected device. An exploit could allow the attacker to cause an interface to become wedged, resulting in an eventual denial of service (DoS) condition on the affected device.

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 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.

A vulnerability in Cisco IOS XE Software for Cisco Catalyst 3650 and Catalyst 3850 Series Switches could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper resource management when processing traffic that is received on the management interface. An attacker could exploit this vulnerability by sending a high rate of traffic to the management interface. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

A vulnerability in the XCP Authentication Service of the Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&P) could allow an unauthenticated, remote attacker to cause a temporary service outage for all Cisco Unified CM IM&P users who are attempting to authenticate to the service, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted login message to the affected device. A successful exploit could allow the attacker to cause an unexpected restart of the authentication service, preventing new users from successfully authenticating. Exploitation of this vulnerability does not impact Cisco Unified CM IM&P users who were authenticated prior to an attack.

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 TCP ingress handler for the data interfaces that are configured with management access to Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an increase in CPU and memory usage, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient ingress TCP rate limiting for TCP ports 22 (SSH) and 443 (HTTPS). An attacker could exploit this vulnerability by sending a crafted, steady stream of TCP traffic to port 22 or 443 on the data interfaces that are configured with management access to the affected device.

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.

A vulnerability in the Snort detection engine integration for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause unlimited memory consumption, which could lead to a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient memory management for certain Snort events. An attacker could exploit this vulnerability by sending a series of crafted IP packets that would generate specific Snort events on an affected device. A sustained attack could cause an out of memory condition on the affected device. A successful exploit could allow the attacker to interrupt all traffic flowing through the affected device. In some circumstances, the attacker may be able to cause the device to reload, resulting in a DoS condition.

A vulnerability in the Snort rule evaluation function 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 improper handling of the DNS reputation enforcement rule. An attacker could exploit this vulnerability by sending crafted UDP packets through an affected device to force a buildup of UDP connections. A successful exploit could allow the attacker to cause traffic that is going through the affected device to be dropped, resulting in a DoS condition. Note: This vulnerability only affects Cisco FTD devices that are running Snort 3.

A vulnerability in the connection handling function in Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper traffic handling when platform limits are reached. An attacker could exploit this vulnerability by sending a high rate of UDP traffic through an affected device. A successful exploit could allow the attacker to cause all new, incoming connections to be dropped, resulting in a DoS condition.

A vulnerability in the web services interface of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected system.  This vulnerability is due to insufficient boundary checks for specific data that is provided to the web services interface of an affected system. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected system. A successful exploit could allow the attacker to cause a buffer overflow condition on the affected system, which could cause the system to reload, resulting in a denial of service (DoS) condition.

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.

A vulnerability in the IP Service Level Agreement (SLA) responder feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the IP SLA responder to reuse an existing port, resulting in a denial of service (DoS) condition. The vulnerability exists because the IP SLA responder could consume a port that could be used by another feature. An attacker could exploit this vulnerability by sending specific IP SLA control packets to the IP SLA responder on an affected device. The control packets must include the port number that could be used by another configured feature. A successful exploit could allow the attacker to cause an in-use port to be consumed by the IP SLA responder, impacting the feature that was using the port and resulting in a DoS condition.

A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is due to the improper processing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to cause an infinite loop that exhausts resources and could cause the device to reload.

A vulnerability in the web UI of Cisco Desk Phone 9800 Series, Cisco IP Phone 7800 and 8800 Series, and Cisco Video Phone 8875 running Cisco SIP Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to a buffer overflow when an affected device processes HTTP packets. An attacker could exploit this vulnerability by sending crafted HTTP input to the device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. Note: To exploit this vulnerability, the phone must be registered to Cisco Unified Communications Manager and have Web Access enabled. Web Access is disabled by default.

A vulnerability in chat messaging features of Cisco Enterprise Chat and Email (ECE) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper validation of user-supplied input to chat entry points. An attacker could exploit this vulnerability by sending malicious requests to a messaging chat entry point in the affected application. A successful exploit could allow the attacker to cause the application to stop responding, resulting in a DoS condition. The application may not recover on its own and may need an administrator to manually restart services to recover.

A vulnerability in the Object Linking and Embedding 2 (OLE2) decryption routine of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an integer underflow in a bounds check that allows for a heap buffer overflow read. An attacker could exploit this vulnerability by submitting a crafted file containing OLE2 content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the ClamAV scanning process, resulting in a DoS condition on the affected software. For a description of this vulnerability, see the . Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

A vulnerability in the management and VPN web servers of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a DoS condition. This vulnerability is due to improper validation of user-supplied input on an interface with VPN web services. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on an affected device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.

A vulnerability in the RADIUS proxy feature for the IPsec VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper processing of IPv6 packets. An attacker could exploit this vulnerability by sending IPv6 packets over an IPsec VPN connection to an affected device. A successful exploit could allow the attacker to trigger a reload of the device, resulting in a DoS condition.

A vulnerability in the packet inspection functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incorrect processing of traffic that is inspected by an affected device. An attacker could exploit this vulnerability by sending crafted traffic through the affected device. A successful exploit could allow the attacker to cause the affected device to enter an infinite loop while inspecting traffic, resulting in a DoS condition. The system watchdog will restart the Snort process automatically.

A vulnerability in the RADIUS message processing feature of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain RADIUS requests. An attacker could exploit this vulnerability by sending a specific authentication request to a network access device (NAD) that uses Cisco ISE for authentication, authorization, and accounting (AAA). A successful exploit could allow the attacker to cause Cisco ISE to reload.

A vulnerability in the function that performs IPv4 and IPv6 Network Address Translation (NAT) DNS inspection for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition.  This vulnerability is due to an infinite loop condition that occurs when a Cisco Secure ASA or Cisco Secure FTD device processes DNS packets with DNS inspection enabled and the device is configured for NAT44, NAT64, or NAT46. An attacker could exploit this vulnerability by sending crafted DNS packets that match a static NAT rule with DNS inspection enabled through an affected device. A successful exploit could allow the attacker to create an infinite loop and cause the device to reload, resulting in a DoS condition.

A vulnerability in the DHCP snooping security feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a full interface queue wedge, which could result in a denial of service (DoS) condition. This vulnerability is due to improper handling of DHCP request packets. An attacker could exploit this vulnerability by sending DHCP request packets to an affected device. A successful exploit could allow the attacker to cause packets to wedge in the queue, creating a DoS condition for downstream devices of the affected system and requiring that the system restart to drain the queue. Note: This vulnerability can be exploited with either unicast or broadcast DHCP packets on a VLAN that does not have DHCP snooping enabled.

A vulnerability in the Network-Based Application Recognition (NBAR) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, causing a denial of service (DoS) condition. This vulnerability is due to improper handling of malformed Control and Provisioning of Wireless Access Points (CAPWAP) packets. An attacker could exploit this vulnerability by sending malformed CAPWAP packets through an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.

A vulnerability in the RADIUS setting Reject RADIUS requests from clients with repeated failures on Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause Cisco ISE to restart unexpectedly. This vulnerability is due to a logic error when processing a RADIUS access request for a MAC address that is already a rejected endpoint. An attacker could exploit this vulnerability by sending a specific sequence of multiple crafted RADIUS access request messages to Cisco ISE. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when Cisco ISE restarts.

A vulnerability in the Two-Way Active Measurement Protocol (TWAMP) server feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. For Cisco IOS XR Software, this vulnerability could cause the ipsla_ippm_server process to reload unexpectedly if debugs are enabled. This vulnerability is due to out-of-bounds array access when processing specially crafted TWAMP control packets. An attacker could exploit this vulnerability by sending crafted TWAMP control packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: For Cisco IOS XR Software, only the ipsla_ippm_server process reloads unexpectedly and only when debugs are enabled. The vulnerability details for Cisco IOS XR Software are as follows:    Security Impact Rating (SIR): Low    CVSS Base Score: 3.7    CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition in the Cisco AnyConnect service on an affected device. This vulnerability is due to variable initialization errors when an SSL VPN session is established. An attacker could exploit this vulnerability by sending a sequence of crafted HTTPS requests to an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to restart, resulting in the failure of all established SSL VPN sessions and forcing remote users to initiate a new VPN connection and re-authenticate. A sustained attack could prevent new SSL VPN connections from being established, effectively making the Cisco AnyConnect VPN service unavailable for all legitimate users.

A vulnerability in the SIP processing subsystem of Cisco BroadWorks could allow an unauthenticated, remote attacker to halt the processing of incoming SIP requests, resulting in a denial of service (DoS) condition. This vulnerability is due to improper memory handling for certain SIP requests. An attacker could exploit this vulnerability by sending a high number of SIP requests to an affected system. A successful exploit could allow the attacker to exhaust the memory that was allocated to the Cisco BroadWorks Network Servers that handle SIP traffic. If no memory is available, the Network Servers can no longer process incoming requests, resulting in a DoS condition that requires manual intervention to recover.

Unspecified Cisco Catalyst Switches allow remote attackers to cause a denial of service (device crash) via an IP packet with the same source and destination IPs and ports, and with the SYN flag set (aka LanD). NOTE: the provenance of this issue is unknown; the details are obtained solely from the BID.

Memory leak in Cisco Prime Central for Hosted Collaboration Solution (HCS) Assurance 8.6 and 9.x before 9.2(1) allows remote attackers to cause a denial of service (memory consumption) via a flood of TCP packets, aka Bug ID CSCub59158.

Cisco TelePresence TC Software before 6.1 and TE Software before 4.1.3 allow remote attackers to cause a denial of service (temporary device hang) via crafted SIP packets, aka Bug ID CSCuf89557.

The IronPort Spam Quarantine (ISQ) component in the web framework in IronPort AsyncOS on Cisco Email Security Appliance devices before 7.1.5-106 and 7.3, 7.5, and 7.6 before 7.6.3-019 and Content Security Management Appliance devices before 7.9.1-102 and 8.0 before 8.0.0-404 allows remote attackers to cause a denial of service (service crash or hang) via a high rate of TCP connection attempts, aka Bug IDs CSCzv25573 and CSCzv81712.