A vulnerability in the Protocol Independent Multicast (PIM) feature for IPv6 networks (PIM6) 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 improper error handling when processing inbound PIM6 packets. An attacker could exploit this vulnerability by sending multiple crafted PIM6 packets to an affected device. A successful exploit could allow the attacker to cause the PIM6 application to leak system memory. Over time, this memory leak could cause the PIM6 application to stop processing legitimate PIM6 traffic, leading to a DoS condition on the affected device.

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol handler of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of CAPWAP packets. An attacker could exploit this vulnerability by sending a malformed CAPWAP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to restart, resulting in a 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.

A vulnerability in DNS over IPv6 packet processing for Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to improper length validation of a field in an IPv6 DNS packet. An attacker could exploit this vulnerability by sending a crafted DNS query over IPv6, which traverses the affected device. An exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is specific to DNS over IPv6 traffic only.

Multiple vulnerabilities in the REST API of Cisco UCS Director and Cisco UCS Director Express for Big Data may allow a remote attacker to bypass authentication or conduct directory traversal attacks on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

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 Internet Key Exchange Version 2 (IKEv2) implementation in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to prevent IKEv2 from establishing new security associations. The vulnerability is due to incorrect handling of crafted IKEv2 SA-Init packets. An attacker could exploit this vulnerability by sending crafted IKEv2 SA-Init packets to the affected device. An exploit could allow the attacker to cause the affected device to reach the maximum incoming negotiation limits and prevent further IKEv2 security associations from being formed.

A vulnerability in the ssl_inspection component of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to crash Snort instances. The vulnerability is due to insufficient input validation in the ssl_inspection component. An attacker could exploit this vulnerability by sending a malformed TLS packet through a Cisco Adaptive Security Appliance (ASA). A successful exploit could allow the attacker to crash a Snort instance, resulting in a denial of service (DoS) condition.

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 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 Secure Sockets Layer (SSL)/Transport Layer Security (TLS) handler of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to exhaust memory resources on the affected device, leading to a denial of service (DoS) condition. The vulnerability is due to improper resource management for inbound SSL/TLS connections. An attacker could exploit this vulnerability by establishing multiple SSL/TLS connections with specific conditions to the affected device. A successful exploit could allow the attacker to exhaust the memory on the affected device, causing the device to stop accepting new SSL/TLS connections and resulting in a DoS condition for services on the device that process SSL/TLS traffic. Manual intervention is required to recover an affected device.

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 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 ARJ archive parsing module in Clam AntiVirus (ClamAV) Software versions 0.102.2 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to a heap buffer overflow read. An attacker could exploit this vulnerability by sending a crafted ARJ 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 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.

A vulnerability in the Polaris kernel of Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to crash the device. The vulnerability is due to insufficient packet size validation. An attacker could exploit this vulnerability by sending jumbo frames or frames larger than the configured MTU size to the management interface of this device. A successful exploit could allow the attacker to crash the device fully before an automatic recovery.

A vulnerability in the implementation of the Border Gateway Protocol (BGP) module in 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. The vulnerability is due to incorrect processing of certain BGP packets. An attacker could exploit this vulnerability by sending a crafted BGP packet. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

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.

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 Snort 2 and Snort 3 TCP and UDP detection engine of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Appliances could allow an unauthenticated, remote attacker to cause memory corruption, which could cause the Snort detection engine to restart unexpectedly. This vulnerability is due to improper memory management when the Snort detection engine processes specific TCP or UDP packets. An attacker could exploit this vulnerability by sending crafted TCP or UDP packets through a device that is inspecting traffic using the Snort detection engine. A successful exploit could allow the attacker to restart the Snort detection engine repeatedly, which could cause a denial of service (DoS) condition. The DoS condition impacts only the traffic through the device that is examined by the Snort detection engine. The device can still be managed over the network. Note: Once a memory block is corrupted, it cannot be cleared until the Cisco Firepower 2100 Series Appliance is manually reloaded. This means that the Snort detection engine could crash repeatedly, causing traffic that is processed by the Snort detection engine to be dropped until the device is manually reloaded.

A vulnerability in the process that classifies traffic that is going to the Unified Threat Defense (UTD) component of Cisco IOS XE Software in controller mode could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because UTD improperly handles certain packets as those packets egress an SD-WAN IPsec tunnel. An attacker could exploit this vulnerability by sending crafted traffic through an SD-WAN IPsec tunnel that is configured on an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. Note: SD-WAN tunnels that are configured with Generic Routing Encapsulation (GRE) are not affected by this vulnerability.

A vulnerability in the DHCP Snooping feature of Cisco IOS XE Software on Software-Defined Access (SD-Access) fabric edge nodes could allow an unauthenticated, remote attacker to cause high CPU utilization on an affected device, resulting in a denial of service (DoS) condition that requires a manual reload to recover. This vulnerability is due to improper handling of IPv4 DHCP packets. An attacker could exploit this vulnerability by sending certain IPv4 DHCP packets to an affected device. A successful exploit could allow the attacker to cause the device to exhaust CPU resources and stop processing traffic, resulting in a DoS condition that requires a manual reload to recover.

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to upload arbitrary-sized files to specific folders on an affected device, which could lead to an unexpected device reload. The vulnerability exists because the affected software does not efficiently handle the writing of large files to specific folders on the local file system. An attacker could exploit this vulnerability by uploading files to those specific folders. A successful exploit could allow the attacker to write a file that triggers a watchdog timeout, which would cause the device to unexpectedly reload, causing a denial of service (DoS) condition.

A vulnerability in the External Agent Assignment Service (EAAS) feature of Cisco Enterprise Chat and Email (ECE) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation of Media Routing Peripheral Interface Manager (MR PIM) traffic that is received by an affected device. An attacker could exploit this vulnerability by sending crafted MR PIM traffic to an affected device. A successful exploit could allow the attacker to trigger a failure on the MR PIM connection between Cisco ECE and Cisco Unified Contact Center Enterprise (CCE), leading to a DoS condition on EAAS that would prevent customers from starting chat, callback, or delayed callback sessions. Note: When the attack traffic stops, the EAAS process must be manually restarted to restore normal operation. To restart the process in the System Console, choose Shared Resources > Services > Unified CCE > EAAS, then click Start.

Multiple vulnerabilities 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 DoS condition in the AnyConnect service on an affected device. These vulnerabilities are due to insufficient validation of client-supplied parameters while establishing an SSL VPN session. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to restart, resulting in the failure of the established SSL VPN connections and forcing remote users to initiate a new VPN connection and reauthenticate. A sustained attack could prevent new SSL VPN connections from being established. Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

A vulnerability in the IPv4 Software-Defined Access (SD-Access) fabric edge node feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause high CPU utilization and stop all traffic processing, resulting in a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain IPv4 packets. An attacker could exploit this vulnerability by sending certain IPv4 packets to an affected device. A successful exploit could allow the attacker to cause the device to exhaust CPU resources and stop processing traffic, resulting in a DoS condition.

Multiple vulnerabilities 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 DoS condition in the AnyConnect service on an affected device. These vulnerabilities are due to insufficient validation of client-supplied parameters while establishing an SSL VPN session. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to restart, resulting in the failure of the established SSL VPN connections and forcing remote users to initiate a new VPN connection and reauthenticate. A sustained attack could prevent new SSL VPN connections from being established. Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

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 multicast DNS (mDNS) feature 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. The vulnerability is due to improper validation of mDNS packets. An attacker could exploit this vulnerability by sending a crafted mDNS packet to an affected device. A successful exploit could cause a device to reload, resulting in a DoS condition.

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 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 Secure Sockets Layer (SSL) VPN feature for Cisco Small Business RV VPN Routers could allow an unauthenticated, remote attacker to cause the device to unexpectedly restart, causing 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 over an SSL connection to the targeted device. A successful exploit could allow the attacker to cause a reload, resulting in a DoS condition.

A vulnerability with the handling of MPLS traffic for Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause the netstack process to unexpectedly restart, which could cause the device to stop processing network traffic or to reload. This vulnerability is due to lack of proper error checking when processing an ingress MPLS frame. An attacker could exploit this vulnerability by sending a crafted IPv6 packet that is encapsulated within an MPLS frame to an MPLS-enabled interface of the targeted device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition. Note: The IPv6 packet can be generated multiple hops away from the targeted device and then encapsulated within MPLS. The DoS condition may occur when the NX-OS device processes the packet.

A vulnerability in the IKEv1 fragmentation code of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a heap underflow, resulting in an affected device reloading. This vulnerability exists because crafted, fragmented IKEv1 packets are not properly reassembled. An attacker could exploit this vulnerability by sending crafted UDP packets to an affected system. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: Only traffic that is directed to the affected system can be used to exploit this vulnerability. This vulnerability can be triggered by IPv4 and IPv6 traffic..

A vulnerability in the PDF parsing module of Clam AntiVirus (ClamAV) versions 1.4.0, 1.3.2 and prior versions, all 1.2.x versions, 1.0.6 and prior versions, all 0.105.x versions, all 0.104.x versions, and 0.103.11 and all prior versions could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to an out of bounds read. An attacker could exploit this vulnerability by submitting a crafted PDF file to be scanned by ClamAV on an affected device. An exploit could allow the attacker to terminate the scanning process.

A vulnerability in the HTML parser of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to an issue in the C to Rust foreign function interface. An attacker could exploit this vulnerability by submitting a crafted file containing HTML content to be scanned by ClamAV on an affected device. An exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.

A vulnerability in the web-based management interface of Cisco IP Phone firmware could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a DoS condition. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted request to the web-based management interface of an affected device. A successful exploit could allow the attacker to cause the affected device to reload.

A vulnerability in the IKEv1 fragmentation code of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a heap overflow, resulting in an affected device reloading. This vulnerability exists because crafted, fragmented IKEv1 packets are not properly reassembled. An attacker could exploit this vulnerability by sending crafted UDP packets to an affected system. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: Only traffic that is directed to the affected system can be used to exploit this vulnerability. This vulnerability can be triggered by IPv4 and IPv6 traffic.

A vulnerability in the OLE2 file format parser 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 incorrect check for end-of-string values during scanning, which may result in a heap buffer over-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 cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software and consuming available system resources. For a description of this vulnerability, see the ClamAV blog .

A vulnerability in the certificate processing 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 the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper parsing of SSL/TLS certificates. An attacker could exploit this vulnerability by sending crafted DNS packets that match a static Network Address Translation (NAT) rule with DNS inspection enabled through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

The HTTP framework on Cisco SPA300, SPA500, and SPA51x devices allows remote attackers to cause a denial of service (device outage) via a series of malformed HTTP requests, aka Bug ID CSCut67385.

The Wide Area Application Services (WAAS) Express implementation in Cisco IOS 15.1 through 15.5 allows remote attackers to cause a denial of service (device reload) via a crafted TCP segment, aka Bug ID CSCuq59708.

The Locator/ID Separation Protocol (LISP) implementation in Cisco IOS 15.1 and 15.2 and NX-OS 4.1 through 6.2 allows remote attackers to cause a denial of service (device reload) via a crafted header in a packet, aka Bug ID CSCuu64279.

A vulnerability in the common Session Initiation Protocol (SIP) library of Cisco IOS and 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 insufficient sanity checks on an internal data structure. An attacker could exploit this vulnerability by sending a sequence of malicious SIP messages to an affected device. An exploit could allow the attacker to cause a NULL pointer dereference, resulting in a crash of the iosd process. This triggers a reload of the device.

A vulnerability in confederation implementation for the Border Gateway Protocol (BGP) in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to a memory corruption that occurs when a BGP update is created with an AS_CONFED_SEQUENCE attribute that has 255 autonomous system numbers (AS numbers). An attacker could exploit this vulnerability by sending a crafted BGP update message, or the network could be designed in such a manner that the AS_CONFED_SEQUENCE attribute grows to 255 AS numbers or more. A successful exploit could allow the attacker to cause memory corruption, which may cause the BGP process to restart, resulting in a DoS condition. To exploit this vulnerability, an attacker must control a BGP confederation speaker within the same autonomous system as the victim, or the network must be designed in such a manner that the AS_CONFED_SEQUENCE attribute grows to 255 AS numbers or more.

A vulnerability in the crypto engine of the Cisco Integrated Services Module for VPN (ISM-VPN) running Cisco IOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient handling of VPN traffic by the affected device. An attacker could exploit this vulnerability by sending crafted VPN traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to hang or crash, resulting in a DoS condition. Cisco Bug IDs: CSCvd39267.