The data-link switching (DLSw) component in Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service (device restart or memory consumption) via crafted (1) UDP port 2067 or (2) IP protocol 91 packets.

Memory leak in the crypto functionality in Cisco Adaptive Security Appliance (ASA) 5500 devices 7.2 before 7.2(4)2, 8.0 before 8.0(3)14, and 8.1 before 8.1(1)4, when configured as a clientless SSL VPN endpoint, allows remote attackers to cause a denial of service (memory consumption and VPN hang) via a crafted SSL or HTTP packet, aka Bug ID CSCso66472.

A vulnerability in Cisco Meeting Server versions prior to 2.2.2 could allow an authenticated, remote attacker to cause the system to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to video calls being made on systems with a particular configuration. An attacker could exploit this by knowing a valid URI that directs to a Cisco Meeting Server. An attacker could then make a video call and cause the system to reload. Cisco Bug IDs: CSCve65931.

The virtual private dial-up network (VPDN) component in Cisco IOS before 12.3 allows remote attackers to cause a denial of service (resource exhaustion) via a series of PPTP sessions, related to the persistence of interface descriptor block (IDB) data structures after process termination, aka bug ID CSCdv59309.

Multiple vulnerabilities in Cisco Jabber for Windows, Cisco Jabber for Mac, and Cisco Jabber for mobile platforms could allow an attacker to access sensitive information or cause a denial of service (DoS) condition. For more information about these vulnerabilities, see the Details section of this advisory.

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.

Multiple vulnerabilities in the ingress packet processing function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to 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 CLI management in Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to access the underlying operating system as the root user. This vulnerability is due to the way the software handles concurrent CLI sessions. An attacker could exploit this vulnerability by authenticating to the device as an administrative user and executing a sequence of commands. A successful exploit could allow the attacker to obtain access to the underlying operating system as the root user.

A vulnerability in Address Resolution Protocol (ARP) management of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to prevent an affected device from resolving ARP entries for legitimate hosts on the connected subnets. This vulnerability exists because ARP entries are mismanaged. An attacker could exploit this vulnerability by continuously sending traffic that results in incomplete ARP entries. A successful exploit could allow the attacker to cause ARP requests on the device to be unsuccessful for legitimate hosts, resulting in a denial of service (DoS) condition.

A vulnerability in the ingress traffic manager of Cisco IOS XE Software for Cisco Network Convergence System (NCS) 520 Routers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition in the web management interface of an affected device. This vulnerability is due to incorrect processing of certain IPv4 TCP traffic that is destined to an affected device. An attacker could exploit this vulnerability by sending a large number of crafted TCP packets to the affected device. A successful exploit could allow the attacker to cause the web management interface to become unavailable, resulting in a DoS condition. Note: This vulnerability does not impact traffic that is going through the device or going to the Management Ethernet interface of the device.

Cisco Systems VPN Client IPSec Driver (CVPNDRVA.sys) 5.0.02.0090 allows local users to cause a denial of service (crash) by calling the 0x80002038 IOCTL with a small size value, which triggers memory corruption.

Memory leak on the Cisco Wireless LAN Controller (WLC) platform 4.x before 4.2.205.0, 5.1 before 5.1.163.0, and 5.0 and 5.2 before 5.2.178.0, as used in Cisco 1500 Series, 2000 Series, 2100 Series, 4100 Series, 4200 Series, and 4400 Series Wireless Services Modules (WiSM), WLC Modules for Integrated Services Routers, and Catalyst 3750G Integrated Wireless LAN Controllers, allows remote attackers to cause a denial of service (memory consumption and device reload) via SSH management connections, aka Bug ID CSCsw40789.

A vulnerability in the IPsec Manager of Cisco StarOS for Cisco Aggregation Services Router (ASR) 5000 Series Routers and Virtualized Packet Core (VPC) System Software could allow an unauthenticated, remote attacker to terminate all active IPsec VPN tunnels and prevent new tunnels from being established, resulting in a denial of service (DoS) condition. The vulnerability is due to improper processing of corrupted Internet Key Exchange Version 2 (IKEv2) messages. An attacker could exploit this vulnerability by sending crafted IKEv2 messages toward an affected router. A successful exploit could allow the attacker to cause the ipsecmgr service to reload. A reload of this service could cause all IPsec VPN tunnels to be terminated and prevent new tunnels from being established until the service has restarted, resulting in a DoS condition. This vulnerability affects the following Cisco products when they are running Cisco StarOS: Cisco Aggregation Services Router (ASR) 5000 Series Routers, Virtualized Packet Core (VPC) System Software. Cisco Bug IDs: CSCve29605.

Cisco IOS 12.0(32)S12 through 12.0(32)S13 and 12.0(33)S3 through 12.0(33)S4, 12.0(32)SY8 through 12.0(32)SY9, 12.2(33)SXI1, 12.2XNC before 12.2(33)XNC2, 12.2XND before 12.2(33)XND1, and 12.4(24)T1; and IOS XE 2.3 through 2.3.1t and 2.4 through 2.4.0; when RFC4893 BGP routing is enabled, allows remote attackers to cause a denial of service (memory corruption and device reload) by using an RFC4271 peer to send an update with a long series of AS numbers, aka Bug ID CSCsy86021.

Memory leak on the Cisco Physical Access Gateway with software before 1.1 allows remote attackers to cause a denial of service (memory consumption) via unspecified TCP packets.

The SSLVPN feature in Cisco IOS 12.3 through 12.4 allows remote attackers to cause a denial of service (device reload or hang) via a crafted HTTPS packet.

Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12.4, when an Easy VPN (aka EZVPN) server is enabled, allows remote attackers to cause a denial of service (memory consumption and device crash) via a sequence of TCP packets.

A vulnerability in the web interface of Cisco IoT Field Network Director could allow an unauthenticated, remote attacker to trigger high CPU usage, resulting in a denial of service (DoS) condition on an affected device. The vulnerability is due to improper handling of Transport Layer Security (TLS) renegotiation requests. An attacker could exploit this vulnerability by sending renegotiation requests at a high rate. A successful exploit could increase the resource usage on the system, eventually leading to a DoS condition.

A vulnerability in the Network Time Protocol (NTP) feature 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 excessive use of system resources when the affected device is logging a drop action for received MODE_PRIVATE (Mode 7) NTP packets. An attacker could exploit this vulnerability by flooding the device with a steady stream of Mode 7 NTP packets. A successful exploit could allow the attacker to cause high CPU and memory usage on the affected device, which could cause internal system processes to restart or cause the affected device to unexpectedly reload. Note: The NTP feature is enabled by default.

A vulnerability in the Cisco Discovery Protocol or Link Layer Discovery Protocol (LLDP) implementation for the Cisco IP Phone 7800 and 8800 Series could allow an unauthenticated, adjacent attacker to cause an affected phone to reload unexpectedly, resulting in a temporary denial of service (DoS) condition. The vulnerability is due to missing length validation of certain Cisco Discovery Protocol or LLDP packet header fields. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol or LLDP packet to the targeted phone. A successful exploit could allow the attacker to cause the affected phone to reload unexpectedly, resulting in a temporary DoS condition. Versions prior to 12.6(1)MN80 are affected.

A vulnerability in the handling of Inter-Access Point Protocol (IAPP) messages by Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. The vulnerability exist because the software improperly validates input on fields within IAPP messages. An attacker could exploit the vulnerability by sending malicious IAPP messages to an affected device. A successful exploit could allow the attacker to cause the Cisco WLC Software to reload, resulting in a DoS condition. Software versions prior to 8.2.170.0, 8.5.150.0, and 8.8.100.0 are affected.

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 handling of Inter-Access Point Protocol (IAPP) messages by Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. The vulnerability exist because the software improperly validates input on fields within IAPP messages. An attacker could exploit the vulnerability by sending malicious IAPP messages to an affected device. A successful exploit could allow the attacker to cause the Cisco WLC Software to reload, resulting in a DoS condition. Software versions prior to 8.2.170.0, 8.5.150.0, and 8.8.100.0 are affected.

A vulnerability in the WebVPN service of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper management of authenticated sessions in the WebVPN portal. An attacker could exploit this vulnerability by authenticating with valid credentials and accessing a specific URL in the WebVPN portal. A successful exploit could allow the attacker to cause the device to reload, resulting in a temporary DoS condition.

A vulnerability in field-programmable gate array (FPGA) ingress buffer management for the Cisco Firepower 9000 Series with the Cisco Firepower 2-port 100G double-width network module (PID: FPR9K-DNM-2X100G) could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. Manual intervention may be required before a device will resume normal operations. The vulnerability is due to a logic error in the FPGA related to the processing of different types of input packets. An attacker could exploit this vulnerability by being on the adjacent subnet and sending a crafted sequence of input packets to a specific interface on an affected device. A successful exploit could allow the attacker to cause a queue wedge condition on the interface. When a wedge occurs, the affected device will stop processing any additional packets that are received on the wedged interface. Version 2.2 is affected.

A vulnerability in the handling of Inter-Access Point Protocol (IAPP) messages by Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. The vulnerability exist because the software improperly validates input on fields within IAPP messages. An attacker could exploit the vulnerability by sending malicious IAPP messages to an affected device. A successful exploit could allow the attacker to cause the Cisco WLC Software to reload, resulting in a DoS condition. Software versions prior to 8.2.170.0, 8.5.150.0, and 8.8.100.0 are affected.

Multiple vulnerabilities in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerabilities are due to incorrect processing of BGP update messages that contain crafted EVPN attributes. An attacker could exploit these vulnerabilities by sending BGP EVPN update messages with malformed attributes 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 these vulnerabilities, 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 implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerabilities are due to incorrect processing of BGP update messages that contain crafted EVPN attributes. An attacker could exploit these vulnerabilities by sending BGP EVPN update messages with malformed attributes 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 these vulnerabilities, 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.

A vulnerability in the call-handling functionality of Session Initiation Protocol (SIP) Software for Cisco IP Phone 7800 Series and 8800 Series could allow an unauthenticated, remote attacker to cause an affected phone to reload unexpectedly, resulting in a temporary denial of service (DoS) condition. The vulnerability is due to incomplete error handling when XML data within a SIP packet is parsed. An attacker could exploit this vulnerability by sending a SIP packet that contains a malicious XML payload to an affected phone. A successful exploit could allow the attacker to cause the affected phone to reload unexpectedly, resulting in a temporary DoS condition.

Multiple vulnerabilities in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerabilities are due to incorrect processing of BGP update messages that contain crafted EVPN attributes. An attacker could exploit these vulnerabilities by sending BGP EVPN update messages with malformed attributes 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 these vulnerabilities, 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 implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerabilities are due to incorrect processing of BGP update messages that contain crafted EVPN attributes. An attacker could exploit these vulnerabilities by sending BGP EVPN update messages with malformed attributes 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 these vulnerabilities, 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.

A vulnerability in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) 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 crafted EVPN attributes. An attacker could indirectly exploit the vulnerability by sending BGP EVPN update messages with a specific, malformed attribute to an affected system and waiting for a user on the device to display the EVPN operational routes’ status. If successful, the attacker could 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.

A vulnerability in the web-based management interface of Cisco SPA100 Series Analog Telephone Adapters (ATAs) could allow an authenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper validation of user-supplied requests to the web-based management interface. 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 device to stop responding, requiring manual intervention for recovery.

A vulnerability in Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an authenticated, remote attacker to access sensitive information. The vulnerability occurs because the affected software does not properly validate user-supplied input. An attacker could exploit this vulnerability by issuing certain commands with filtered query results on the device. This action may cause returned messages to display confidential system information. A successful exploit could allow the attacker to read sensitive information on the device.

A vulnerability in the HTTP client feature of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to read and modify data that should normally have been sent via an encrypted channel. The vulnerability is due to TCP port information not being considered when matching new requests to existing, persistent HTTP connections. An attacker could exploit this vulnerability by acting as a man-in-the-middle and then reading and/or modifying data that should normally have been sent through an encrypted channel.

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.

Cisco Wireless LAN Controller (WLC) before 3.2.116.21, and 4.0.x before 4.0.155.0, allows remote attackers on a local network to cause a denial of service (device crash) via malformed Ethernet traffic.

Multiple vulnerabilities in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerabilities are due to incorrect processing of BGP update messages that contain crafted EVPN attributes. An attacker could exploit these vulnerabilities by sending BGP EVPN update messages with malformed attributes 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 these vulnerabilities, 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.

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).

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 trigger a reload of an affected device, resulting in 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. The attacker does not need valid credentials to authenticate the VPN session, nor does the attacker's source address need to match a peer statement in the crypto map applied to the ingress interface of the affected device. An exploit could allow the attacker to exhaust system memory resources, leading to a reload of an affected device.

The administrative web interface on the Cisco Wireless LAN Controller (WLC) platform 4.2 before 4.2.205.0 and 5.x before 5.2.178.0, as used in Cisco 1500 Series, 2000 Series, 2100 Series, 4100 Series, 4200 Series, and 4400 Series Wireless Services Modules (WiSM), WLC Modules for Integrated Services Routers, and Catalyst 3750G Integrated Wireless LAN Controllers, allows remote attackers to cause a denial of service (device reload) via a malformed response to a (1) HTTP or (2) HTTPS authentication request, aka Bug ID CSCsx03715.

A vulnerability in an API of the Call 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 improper handling of large series of message requests. An attacker could exploit this vulnerability by sending a series of messages to the vulnerable API. A successful exploit could allow the attacker to cause the affected device to reload, dropping all ongoing calls and resulting in a DoS condition.

A vulnerability in the Layer 2 punt code of Cisco IOS XR Software running on Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, adjacent attacker to cause the affected line card to reboot. This vulnerability is due to incorrect handling of specific Ethernet frames that cause a spin loop that can make the network processors unresponsive. An attacker could exploit this vulnerability by sending specific types of Ethernet frames on the segment where the affected line cards are attached. A successful exploit could allow the attacker to cause the affected line card to reboot.

A vulnerability in the Shell Access Filter feature of Cisco Firepower Management Center (FMC), when used in conjunction with remote authentication, could allow an unauthenticated, remote attacker to cause high disk utilization, resulting in a denial of service (DoS) condition. The vulnerability occurs because the configuration of the Shell Access Filter, when used with a specific type of remote authentication, can cause a system file to have unbounded writes. An attacker could exploit this vulnerability by sending a steady stream of remote authentication requests to the appliance when the specific configuration is applied. Successful exploitation could allow the attacker to increase the size of a system log file so that it consumes most of the disk space. The lack of available disk space could lead to a DoS condition in which the device functions could operate abnormally, making the device unstable.

A vulnerability in certain IPv4 fragment-processing functions of Cisco Remote PHY Software could allow an unauthenticated, remote attacker to impact traffic passing through a device, potentially causing a denial of service (DoS) condition. The vulnerability is due to the affected software not validating and calculating certain numerical values in IPv4 packets that are sent to an affected device. An attacker could exploit this vulnerability by sending malformed IPv4 traffic to an affected device. A successful exploit could allow the attacker to disrupt the flow of certain IPv4 traffic passing through an affected device, which could result in a DoS condition.

A vulnerability in the web interface of Cisco Integrated Management Controller (IMC) Supervisor and Cisco UCS Director could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected system. The vulnerability is due to insufficient restrictions on the size or total amount of resources allowed via the web interface. An attacker who has valid credentials for the application could exploit this vulnerability by sending a crafted or malformed HTTP request to the web interface. A successful exploit could allow the attacker to cause oversubscription of system resources or cause a component to become unresponsive, resulting in a DoS condition.