A vulnerability in the Cisco Fabric Services component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability exists because the affected software insufficiently validates Cisco Fabric Services packets. An attacker could exploit this vulnerability by sending a crafted Cisco Fabric Services packet to an affected device. A successful exploit could allow the attacker to force a NULL pointer dereference and cause a DoS condition. This vulnerability affects the following if configured to use Cisco Fabric Services: Firepower 4100 Series Next-Generation Firewalls, Firepower 9300 Security Appliance, MDS 9000 Series Multilayer Switches, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvd69966, CSCve02435, CSCve04859, CSCve41590, CSCve41593, CSCve41601.

A vulnerability in the DHCP version 4 (DHCPv4) server feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to trigger a crash of the dhcpd process, resulting in a denial of service (DoS) condition. This vulnerability exists because certain DHCPv4 messages are improperly validated when they are processed by an affected device. An attacker could exploit this vulnerability by sending a malformed DHCPv4 message to an affected device. A successful exploit could allow the attacker to cause a NULL pointer dereference, resulting in a crash of the dhcpd process. While the dhcpd process is restarting, which may take up to approximately two minutes, DHCPv4 server services are unavailable on the affected device. This could temporarily prevent network access to clients that join the network during that time period. Note: Only the dhcpd process crashes and eventually restarts automatically. The router does not reload.

The do_change_cipher_spec function in OpenSSL 0.9.6c to 0.9.6k, and 0.9.7a to 0.9.7c, allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that triggers a null dereference.

Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the EGG archive parsing module in Clam AntiVirus (ClamAV) Software versions 0.102.0 - 0.102.3 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to a null pointer dereference. An attacker could exploit this vulnerability by sending a crafted EGG file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process crash, resulting in a denial of service condition.

A vulnerability in the Cisco Fabric Services component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated attacker to cause process crashes, which could result in a denial of service (DoS) condition on an affected device. The attack vector is configuration dependent and could be remote or adjacent. For more information about the attack vector, see the Details section of this advisory. The vulnerability is due to insufficient error handling when the affected software parses Cisco Fabric Services messages. An attacker could exploit this vulnerability by sending malicious Cisco Fabric Services messages to an affected device. A successful exploit could allow the attacker to cause a reload of an affected device, which could result in a DoS condition.

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.

A vulnerability in the RESTCONF and NETCONF-YANG access control list (ACL) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload. The vulnerability is due to incorrect processing of the ACL that is tied to the RESTCONF or NETCONF-YANG feature. An attacker could exploit this vulnerability by accessing the device using RESTCONF or NETCONF-YANG. 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 TLS processing feature of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an issue that occurs when TLS traffic is processed. An attacker could exploit this vulnerability by sending certain TLS traffic over IPv4 through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition and impacting traffic to and through the affected device.

A vulnerability in the HTTP Server feature of Cisco IOS XE Software when the Telephony Service feature is enabled could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to a null pointer dereference when accessing specific URLs. An attacker could exploit this vulnerability by sending crafted HTTP traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, causing a DoS condition on the affected device.

A vulnerability in the web server of Cisco Integrated Management Controller (IMC) could allow an unauthenticated, remote attacker to cause the web server process to crash, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to insufficient validation of user-supplied input on the web interface. An attacker could exploit this vulnerability by submitting a crafted HTTP request to certain endpoints of the affected software. A successful exploit could allow an attacker to cause the web server to crash. Physical access to the device may be required for a restart.

A vulnerability in Cisco SIP IP Phone Software for Cisco IP Phone 7800 Series and 8800 Series could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected phone. The vulnerability is due to insufficient validation of input Session Initiation Protocol (SIP) packets. An attacker could exploit this vulnerability by altering the SIP replies that are sent to the affected phone during the registration process. A successful exploit could allow the attacker to cause the phone to reboot and not complete the registration process.

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 Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Wireless Controller Software for the Catalyst 9000 Family could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to inadequate input validation of incoming CAPWAP packets encapsulating multicast DNS (mDNS) queries. An attacker could exploit this vulnerability by connecting to a wireless network and sending a crafted mDNS query, which would flow through and be processed by the wireless controller. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition.

A vulnerability in the TCP proxy functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper handling of TCP flows. An attacker could exploit this vulnerability by sending a crafted stream of TCP traffic through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a 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 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 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 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 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.

The Next-Generation Firewall (aka NGFW, formerly CX Context-Aware Security) module 9.x before 9.1.1.9 and 9.1.2.x before 9.1.2.12 for Cisco Adaptive Security Appliances (ASA) devices allows remote attackers to cause a denial of service (device reload or traffic-processing outage) via fragmented (1) IPv4 or (2) IPv6 traffic, aka Bug ID CSCue88387.

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 to port (1) 61615 or (2) 61616, aka Bug ID CSCtz90114.

Memory leak in Cisco Unified Communications Manager IM and Presence Service before 8.6(5)SU1 and 9.x before 9.1(2), and Cisco Unified Presence, allows remote attackers to cause a denial of service (memory and CPU consumption) by making many TCP connections to port (1) 5060 or (2) 5061, aka Bug ID CSCud84959.

The Cisco Unified IP Phone 8945 with software 9.3(2) allows remote attackers to cause a denial of service (device hang) via a malformed PNG file, aka Bug ID CSCud04270.

Cisco Unified Communications Manager (Unified CM) 7.1(x) before 7.1(5b)su6a does not properly handle errors, which allows remote attackers to cause a denial of service (service disruption) via malformed registration messages, aka Bug ID CSCuf93466.

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 (disk consumption) via a flood of TCP packets to port 5400, leading to large error-log files, aka Bug ID CSCua42724.

Memory leak in Cisco Unified Communications Manager (Unified CM) 8.5(x) before 8.5(1)su6, 8.6(x) before 8.6(2a)su3, and 9.x before 9.1(1) allows remote attackers to cause a denial of service (service disruption) via a high rate of UDP packets, aka Bug ID CSCub85597.

Cisco Wireless LAN Controller (WLC) devices with software 7.0 before 7.0.220.0, 7.1 before 7.1.91.0, and 7.2 before 7.2.103.0 allow remote attackers to cause a denial of service (Access Point reload) via crafted SIP packets, aka Bug ID CSCts87659.

The Wireless Intrusion Prevention System (wIPS) component on Cisco Wireless LAN Controller (WLC) devices with software 7.0 before 7.0.235.0, 7.1 and 7.2 before 7.2.110.0, and 7.3 before 7.3.101.0 allows remote attackers to cause a denial of service (device reload) via crafted IP packets, aka Bug ID CSCtx80743.

Memory leak in Cisco IOS 12.2, 12.4, 15.0, and 15.1, when Zone-Based Policy Firewall SIP application layer gateway inspection is enabled, allows remote attackers to cause a denial of service (memory consumption or device reload) via malformed SIP messages, aka Bug ID CSCtl99174.

Cisco TelePresence Supervisor MSE 8050 before 2.3(1.31) allows remote attackers to cause a denial of service (CPU consumption or device reload) by establishing TCP connections at a high rate, aka Bug IDs CSCuf76076 and CSCuf79763.

Race condition in the VRF-aware NAT feature in Cisco IOS 12.2 through 12.4 and 15.0 through 15.2 allows remote attackers to cause a denial of service (memory consumption) via IPv4 packets, aka Bug IDs CSCtg47129 and CSCtz96745.

The auth-proxy functionality in Cisco Firewall Services Module (FWSM) software 3.1 and 3.2 before 3.2(20.1), 4.0 before 4.0(15.2), and 4.1 before 4.1(5.1) allows remote attackers to cause a denial of service (device reload) via a crafted URL, aka Bug ID CSCtg02624.

The management API in the XML API management service in the Manager component in Cisco Unified Computing System (UCS) 1.x before 1.2(1b) allows remote attackers to cause a denial of service (service outage) via a malformed request, aka Bug ID CSCtg48206.

Cisco Intrusion Prevention System (IPS) Software in ASA 5500-X IPS-SSP software modules before 7.1(7)sp1E4 allows remote attackers to cause a denial of service (Analysis Engine process hang or device reload) via fragmented (1) IPv4 or (2) IPv6 packets, aka Bug ID CSCue51272.

The authentication-proxy implementation on Cisco Adaptive Security Appliances (ASA) devices with software 7.x before 7.2(5.10), 8.0 before 8.0(5.31), 8.1 and 8.2 before 8.2(5.38), 8.3 before 8.3(2.37), 8.4 before 8.4(5.3), 8.5 and 8.6 before 8.6(1.10), 8.7 before 8.7(1.4), 9.0 before 9.0(1.1), and 9.1 before 9.1(1.2) allows remote attackers to cause a denial of service (device reload) via a crafted URL, aka Bug ID CSCud16590.

Cisco Adaptive Security Appliances (ASA) devices with software 7.x before 7.2(5.10), 8.0 before 8.0(5.28), 8.1 and 8.2 before 8.2(5.35), 8.3 before 8.3(2.34), 8.4 before 8.4(4.11), 8.6 before 8.6(1.10), and 8.7 before 8.7(1.3), and Cisco Firewall Services Module (FWSM) software 3.1 and 3.2 before 3.2(24.1) and 4.0 and 4.1 before 4.1(11.1), allow remote attackers to cause a denial of service (device reload) via a crafted IKEv1 message, aka Bug IDs CSCub85692 and CSCud20267.

Cisco IOS XE 2.x and 3.x before 3.4.5S, and 3.5 through 3.7 before 3.7.1S, on 1000 series Aggregation Services Routers (ASR) allows remote attackers to cause a denial of service (card reload) by sending many crafted L2TP packets, aka Bug ID CSCtz23293.

The IP stack in Cisco Intrusion Prevention System (IPS) Software in ASA 5500-X IPS-SSP software and hardware modules before 7.1(5)E4, IPS 4500 sensors before 7.1(6)E4, and IPS 4300 sensors before 7.1(5)E4 allows remote attackers to cause a denial of service (MainApp process hang) via malformed IPv4 packets, aka Bug ID CSCtx18596.

The Smart Install client functionality in Cisco IOS 12.2 and 15.0 through 15.3 on Catalyst switches allows remote attackers to cause a denial of service (device reload) via crafted image list parameters in Smart Install packets, aka Bug ID CSCub55790.