A vulnerability in the Cisco Fabric Services over IP (CFSoIP) feature 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 is due to insufficient validation of incoming CFSoIP packets. An attacker could exploit this vulnerability by sending crafted CFSoIP packets to 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 TCP state machine of Cisco RF Gateway 1 devices could allow an unauthenticated, remote attacker to prevent an affected device from delivering switched digital video (SDV) or video on demand (VoD) streams, resulting in a denial of service (DoS) condition. The vulnerability is due to a processing error with TCP connections to the affected device. An attacker could exploit this vulnerability by establishing a large number of TCP connections to an affected device and not actively closing those TCP connections. A successful exploit could allow the attacker to prevent the affected device from delivering SDV or VoD streams to set-top boxes. Cisco Bug IDs: CSCvf19887.

A vulnerability in Cisco WebEx Meetings Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient limitations on the number of connections that can be made to the affected software. An attacker could exploit this vulnerability by opening multiple connections to the server and exhausting server resources. A successful exploit could cause the server to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvf41006.

A vulnerability in SSL/TLS message handler for 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. This vulnerability exists because incoming SSL/TLS packets are not properly processed. An attacker could exploit this vulnerability by sending a crafted SSL/TLS packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

The Multicast Source Discovery Protocol (MSDP) implementation in Cisco IOS 12.0, 12.2 through 12.4, and 15.0 through 15.2 and IOS XE 2.1.x through 2.6.x and 3.1.xS through 3.4.xS before 3.4.1S and 3.1.xSG and 3.2.xSG before 3.2.2SG allows remote attackers to cause a denial of service (device reload) via encapsulated IGMP data in an MSDP packet, aka Bug ID CSCtr28857.

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 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 email parsing module Clam AntiVirus (ClamAV) Software versions 0.102.0, 0.101.4 and prior could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to inefficient MIME parsing routines that result in extremely long scan times of specially formatted email files. An attacker could exploit this vulnerability by sending a crafted email file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process to scan the crafted email file indefinitely, resulting in a denial of service condition.

The ethernet-lldp component in Cisco IOS 12.2 before 12.2(33)SXJ1 does not properly support a large number of LLDP Management Address (MA) TLVs, which allows remote attackers to cause a denial of service (device crash) via crafted LLDPDUs, aka Bug ID CSCtj22354.

A vulnerability in the HTTP server code of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the HTTP server to crash. The vulnerability is due to a logical error in the logging mechanism. An attacker could exploit this vulnerability by generating a high amount of long-lived connections to the HTTP service on the device. A successful exploit could allow the attacker to cause the HTTP server to crash.

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 system resource management of Cisco Elastic Services Controller (ESC) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) to the health monitor API on an affected device. The vulnerability is due to inadequate provisioning of kernel parameters for the maximum number of TCP connections and SYN backlog. An attacker could exploit this vulnerability by sending a flood of crafted TCP packets to an affected device. A successful exploit could allow the attacker to block TCP listening ports that are used by the health monitor API. This vulnerability only affects customers who use the health monitor API.

Multiple vulnerabilities in Cisco SD-WAN vManage Software could allow an unauthenticated, remote attacker to execute arbitrary code or gain access to sensitive information, or allow an authenticated, local attacker to gain escalated privileges or gain unauthorized access to the application. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the Open Shortest Path First (OSPF) implementation in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a memory leak on an affected device. The vulnerability is due to incorrect processing of certain OSPF packets. An attacker could exploit this vulnerability by sending a series of crafted OSPF packets to be processed by an affected device. A successful exploit could allow the attacker to continuously consume memory on an affected device and eventually cause it to reload, resulting in a denial of service (DoS) condition.

A vulnerability in the Internet Key Exchange version 1 (IKEv1) feature 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. The vulnerability is due to improper management of system memory. An attacker could exploit this vulnerability by sending malicious IKEv1 traffic to an affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

A vulnerability in the web interface of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to trigger high CPU usage, resulting in a denial of service (DoS) condition. The vulnerability is due to improper handling of Secure Sockets Layer (SSL) renegotiation requests. An attacker could exploit this vulnerability by sending renegotiation requests at a high rate. An successful exploit could increase the resource usage on the system, eventually leading to a DoS condition. This vulnerability affects version 2.1.

A vulnerability in the Cisco Fabric Services component of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a buffer overflow, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient validation of 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 cause a buffer overflow, resulting in process crashes and a DoS condition on the device. MDS 9000 Series Multilayer Switches are affected running software versions prior to 6.2(25), 8.1(1b), 8.3(1). Nexus 3000 Series Switches are affected running software versions prior to 7.0(3)I4(9) and 7.0(3)I7(4). Nexus 3500 Platform Switches are affected running software versions prior to 6.0(2)A8(10) and 7.0(3)I7(4). Nexus 3600 Platform Switches are affected running software versions prior to 7.0(3)F3(5) Nexus 7000 and 7700 Series Switches are affected running software versions prior to 6.2(22) and 8.2(3). Nexus 9000 Series Switches in Standalone NX-OS Mode are affected running software versions prior to 7.0(3)I4(9) and 7.0(3)I7(4). Nexus 9500 R-Series Line Cards and Fabric Modules are affected running software versions prior to 7.0(3)F3(5). UCS 6200, 6300, and 6400 Fabric Interconnects are affected running software versions prior to 3.2(3j) and 4.0(2a).

A vulnerability in the software-based SSL/TLS message handler 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, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL/TLS decryption. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: Datagram TLS (DTLS) messages cannot be used to exploit this vulnerability.

A vulnerability in the implementation of the Border Gateway Protocol (BGP) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of a BGP update message that contains a specific BGP attribute. An attacker could exploit this vulnerability by sending BGP update messages that include a specific, malformed attribute to be processed by an affected system. A successful exploit could allow the attacker to cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit this vulnerability, the malicious BGP update message would need to come from a configured, valid BGP peer or would need to be injected by the attacker into the victim’s BGP network on an existing, valid TCP connection to a BGP peer.

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.

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

A vulnerability in the Secure Shell (SSH) session management for 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 exists because the SSH process is not properly deleted when an SSH connection to the device is disconnected. An attacker could exploit this vulnerability by repeatedly opening SSH connections to an affected device. A successful exploit could allow the attacker to exhaust system resources by initiating multiple SSH connections to the device that are not effectively terminated, which could result in a DoS condition.

Multiple vulnerabilities in the video service of Cisco TelePresence Collaboration Endpoint (CE) and Cisco RoomOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerabilities are due to insufficient input validation. An attacker could exploit these vulnerabilities by sending crafted traffic to the video service of an affected endpoint. A successful exploit could allow the attacker to cause the video service to crash, resulting in a DoS condition on an affected device.

Cisco Catalyst LAN switches running Catalyst 5000 supervisor software allows remote attackers to perform a denial of service by forcing the supervisor module to reload.

Denial of service in Cisco IOS web server allows attackers to reboot the router using a long URL.

A vulnerability in the IPsec component of StarOS for Cisco ASR 5000 Series routers could allow an unauthenticated, remote attacker to terminate all active IPsec VPN tunnels and prevent new tunnels from establishing, resulting in a denial of service (DoS) condition. This vulnerability affects the following Cisco products: Cisco ASR 5000/5500 Series routers, Cisco Virtualized Packet Core (VPC). More Information: CSCva13631. Known Affected Releases: 20.0.0 20.1.0 20.2.0 20.2.3 20.2.v1 21.0.0 21.0.M0.64246. Known Fixed Releases: 20.2.3 20.2.3.65026 20.2.a4.65307 20.2.v1 20.2.v1.65353 20.3.M0.65037 20.3.T0.65043 21.0.0 21.0.0.65256 21.0.M0.64595 21.0.M0.64860 21.0.M0.65140 21.0.V0.65052 21.0.V0.65150 21.0.V0.65366 21.0.VC0.64639 21.1.A0.64861 21.1.A0.65145 21.1.PP0.65270 21.1.R0.65130 21.1.R0.65135 21.1.R0.65154 21.1.VC0.64898 21.1.VC0.65203 21.2.A0.65147.

Unspecified vulnerability in Cisco ASA 5500 Series Adaptive Security Appliance 7.0 before 7.0(8.10), 7.2 before 7.2(4.45), 8.0 before 8.0(5.1), 8.1 before 8.1(2.37), and 8.2 before 8.2(1.15); and Cisco PIX 500 Series Security Appliance; allows remote attackers to cause a denial of service (active IPsec tunnel loss and prevention of new tunnels) via a malformed IKE message through an existing tunnel to UDP port 4500, aka Bug ID CSCtc47782.

A vulnerability in the Session Initiation Protocol (SIP) inspection module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper parsing of SIP messages. An attacker could exploit this vulnerability by sending a malicious SIP packet through an affected device. A successful exploit could allow the attacker to trigger an integer underflow, causing the software to try to read unmapped memory and resulting in a crash.

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 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 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.

Multiple vulnerabilities in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to insufficient validation of CAPWAP packets. An attacker could exploit the vulnerabilities by sending a malformed CAPWAP packet to an affected device. 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 web-based management interface of Cisco Integrated Management Controller (IMC) Supervisor, Cisco UCS Director, and Cisco UCS Director Express for Big Data could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to a missing authentication check in an API call. An attacker who can send a request to an affected system could cause all currently authenticated users to be logged off. Repeated exploitation could cause the inability to maintain a session in the web-based management portal.

A vulnerability in the 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.

Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allow remote attackers to cause a denial of service (ASDM syslog outage) via a long URL, aka Bug IDs CSCsm11264 and CSCtb92911.

A vulnerability in the Protection Against Distributed Denial of Service Attacks feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct denial of service (DoS) attacks to or through the affected device. This vulnerability is due to incorrect programming of the half-opened connections limit, TCP SYN flood limit, or TCP SYN cookie features when the features are configured in vulnerable releases of Cisco IOS XE Software. An attacker could exploit this vulnerability by attempting to flood traffic to or through the affected device. A successful exploit could allow the attacker to initiate a DoS attack to or through an affected device.

A vulnerability in the proxy service of Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to exhaust system memory and cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper memory management in the proxy service of an affected device. An attacker could exploit this vulnerability by establishing a large number of HTTPS connections to the affected device. A successful exploit could allow the attacker to cause the system to stop processing new connections, which could result in a DoS condition. Note: Manual intervention may be required to recover from this situation.

A vulnerability in the TCP Normalizer of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software operating in transparent mode could allow an unauthenticated, remote attacker to poison MAC address tables, resulting in a denial of service (DoS) vulnerability. This vulnerability is due to incorrect handling of certain TCP segments when the affected device is operating in transparent mode. An attacker could exploit this vulnerability by sending a crafted TCP segment through an affected device. A successful exploit could allow the attacker to poison the MAC address tables in adjacent devices, resulting in network disruption.

A vulnerability in the web-based management interface of Cisco Integrated Management Controller (IMC) Software could allow an unauthenticated, remote attacker to cause the web-based management interface to unexpectedly restart. The vulnerability is due to insufficient input validation on the web-based management interface. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to cause the interface to restart, resulting in a denial of service (DoS) condition.

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 DoS condition for targeted users of the AnyConnect service on an affected device. This vulnerability is due to insufficient entropy for handlers that are used during SSL VPN session establishment. An unauthenticated attacker could exploit this vulnerability by brute forcing valid session handlers. An authenticated attacker could exploit this vulnerability by connecting to the AnyConnect VPN service of an affected device to retrieve a valid session handler and, based on that handler, predict further valid session handlers. The attacker would then send a crafted HTTPS request using the brute-forced or predicted session handler to the AnyConnect VPN server of the device. A successful exploit could allow the attacker to terminate targeted SSL VPN sessions, forcing remote users to initiate new VPN connections and reauthenticate.

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.

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and 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 input validation when parsing HTTPS requests. An attacker could exploit this vulnerability by sending a malicious HTTPS request to 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 implementation of the Short Message Service (SMS) handling functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. The vulnerability is due to improper processing of SMS protocol data units (PDUs) that are encoded with a special character set. An attacker could exploit this vulnerability by sending a malicious SMS message to an affected device. A successful exploit could allow the attacker to cause the wireless WAN (WWAN) cellular interface module on an affected device to crash, resulting in a DoS condition that would require manual intervention to restore normal operating conditions.

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 AutoIt module 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 a logic error in the memory management of an affected device. An attacker could exploit this vulnerability by submitting a crafted AutoIt file to be scanned by ClamAV on the affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to restart unexpectedly, resulting in a DoS condition.

A vulnerability in an API of the Web Bridge feature of Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to insufficient validation of HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP packets to an affected device. A successful exploit could allow the attacker to cause a partial availability condition, which could cause ongoing video calls to be dropped due to the invalid packets reaching the Web Bridge.