A vulnerability in the Simple Network Management Protocol (SNMP) service of Cisco FXOS Software for Firepower 4100 Series and Firepower 9300 Security Appliances and of Cisco UCS 6300 Series Fabric Interconnects could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to the improper handling of specific SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: This vulnerability affects all supported SNMP versions. To exploit this vulnerability through SNMPv2c or earlier, an attacker must know the SNMP community string that is configured on an affected device. To exploit this vulnerability through SNMPv3, the attacker must have valid credentials for an SNMP user who is configured on the affected device.

A vulnerability in the Link Layer Discovery Protocol (LLDP) message parser of Cisco IOS Software and Cisco IOS XE Software could allow an attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to improper initialization of a buffer. An attacker could exploit this vulnerability via any of the following methods: An authenticated, remote attacker could access the LLDP neighbor table via either the CLI or SNMP while the device is in a specific state. An unauthenticated, adjacent attacker could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then waiting for an administrator of the device or a network management system (NMS) managing the device to retrieve the LLDP neighbor table of the device via either the CLI or SNMP. An authenticated, adjacent attacker with SNMP read-only credentials or low privileges on the device CLI could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then accessing the LLDP neighbor table via either the CLI or SNMP. A successful exploit could allow the attacker to cause the affected device to crash, resulting in a reload of the device.

A vulnerability in Locally Significant Certificate (LSC) management for the Cisco Wireless LAN Controller (WLC) could allow an authenticated, remote attacker to cause the device to unexpectedly restart, which causes a denial of service (DoS) condition. The attacker would need to have valid administrator credentials. The vulnerability is due to incorrect input validation of the HTTP URL used to establish a connection to the LSC Certificate Authority (CA). An attacker could exploit this vulnerability by authenticating to the targeted device and configuring a LSC certificate. An exploit could allow the attacker to cause a DoS condition due to an unexpected restart of the device.

The SNMP module in Cisco IOS XE 3.5E allows remote authenticated users to cause a denial of service (device reload) by polling frequently, aka Bug ID CSCug65204.

Cisco Intrusion Prevention System (IPS) Software allows remote attackers to cause a denial of service (MainApp process outage) via malformed SNMP packets, aka Bug IDs CSCum52355 and CSCul49309.

Cisco Adaptive Security Appliance (ASA) Software 9.0 through 9.5.1 mishandles IPsec error processing, which allows remote authenticated users to cause a denial of service (memory consumption) via crafted (1) LAN-to-LAN or (2) Remote Access VPN tunnel packets, aka Bug ID CSCuv70576.

The XML parser in Cisco Adaptive Security Appliance (ASA) Software through 9.5.2 allows remote authenticated users to cause a denial of service (instability, memory consumption, or device reload) by leveraging (1) administrative access or (2) Clientless SSL VPN access to provide a crafted XML document, aka Bug ID CSCut14209.

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 the web interface of Cisco Wireless LAN Controller Software could allow a low-privileged, authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability exists due to a failure of the HTTP parsing engine to handle specially crafted URLs. An attacker could exploit this vulnerability by authenticating with low privileges to an affected controller and submitting the crafted URL to the web interface of the affected device. Conversely, an unauthenticated attacker could exploit this vulnerability by persuading a user of the web interface to click the crafted URL. A successful exploit could allow the attacker to cause an unexpected restart of the device, resulting in a DoS condition.

Cisco IOS before 15.2(4)S6 does not initialize an unspecified variable, which might allow remote authenticated users to cause a denial of service (CPU consumption, watchdog timeout, crash) by walking specific SNMP objects.

A vulnerability in the Virtual Shell (VSH) session management for Cisco NX-OS Software could allow an authenticated, remote attacker to cause a VSH process to fail to delete upon termination. This can lead to a build-up of VSH processes that overtime can deplete system memory. When there is no system memory available, this can cause unexpected system behaviors and crashes. The vulnerability is due to the VSH process not being properly deleted when a remote management connection to the device is disconnected. An attacker could exploit this vulnerability by repeatedly performing a remote management connection to the device and terminating the connection in an unexpected manner. A successful exploit could allow the attacker to cause the VSH processes to fail to delete, which can lead to a system-wide denial of service (DoS) condition. The attacker must have valid user credentials to log in to the device using the remote management connection.

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of Cisco Small Business Sx200, Sx300, Sx500, ESW2 Series Managed Switches and Small Business Sx250, Sx350, Sx550 Series Switches could allow an authenticated, remote attacker to cause the SNMP application of an affected device to cease processing traffic, resulting in the CPU utilization reaching one hundred percent. Manual intervention may be required before a device resumes normal operations. The vulnerability is due to improper validation of SNMP protocol data units (PDUs) in SNMP packets. An attacker could exploit this vulnerability by sending a malicious SNMP packet to an affected device. A successful exploit could allow the attacker to cause the device to cease forwarding traffic, which could result in a denial of service (DoS) condition. Cisco has released firmware updates that address this vulnerability.

A vulnerability in the XML API of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker to cause the CPU to increase to 100% utilization, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to improper handling of the XML input. An attacker could exploit this vulnerability by sending a specifically crafted XML payload. A successful exploit could allow the attacker to exhaust CPU resources, resulting in a DoS condition until the system is manually rebooted. Software versions prior to X12.5.1 are affected.

A vulnerability in the web proxy functionality of Cisco AsyncOS Software for Cisco Web Security Appliance (WSA) could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient input validation mechanisms for certain fields in HTTP/HTTPS requests sent through an affected device. A successful attacker could exploit this vulnerability by sending a malicious HTTP/HTTPS request through an affected device. An exploit could allow the attacker to force the device to stop processing traffic, resulting in a DoS condition.

A vulnerability in the implementation of the Intermediate System–to–Intermediate System (IS–IS) routing protocol functionality in Cisco IOS XR Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition in the IS–IS process. The vulnerability is due to improper handling of a Simple Network Management Protocol (SNMP) request for specific Object Identifiers (OIDs) by the IS–IS process. An attacker could exploit this vulnerability by sending a crafted SNMP request to the affected device. A successful exploit could allow the attacker to cause a DoS condition in the IS–IS process.

A vulnerability in the web application of Cisco TelePresence Advanced Media Gateway could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to the lack of input validation in the web application. An attacker could exploit this vulnerability by sending a crafted authenticated HTTP request to the device. An exploit could allow the attacker to stop services on an affected device. The device may become inoperable and results in a denial of service (DoS) condition.

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.

Buffer overflow in the web-based management interface on Cisco RV110W devices with firmware through 1.2.1.4, RV130W devices with firmware through 1.0.2.7, and RV215W devices with firmware through 1.3.0.7 allows remote authenticated users to cause a denial of service (device reload) via a crafted HTTP request, aka Bug ID CSCux86669.

A vulnerability in the Internet Key Exchange Version 1 (IKEv1) XAUTH code of Cisco ASA Software could allow an authenticated, remote attacker to cause a reload of an affected system. The vulnerability is due to insufficient validation of the IKEv1 XAUTH parameters passed during an IKEv1 negotiation. An attacker could exploit this vulnerability by sending crafted parameters. Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability only affects systems configured in routed firewall mode and in single or multiple context mode. This vulnerability can be triggered by IPv4 or IPv6 traffic. A valid IKEv1 Phase 1 needs to be established to exploit this vulnerability, which means that an attacker would need to have knowledge of a pre-shared key or have a valid certificate for phase 1 authentication. This vulnerability affects Cisco ASA Software running on the following products: Cisco ASA 1000V Cloud Firewall, Cisco ASA 5500 Series Adaptive Security Appliances, Cisco ASA 5500-X Series Next-Generation Firewalls, Cisco ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Cisco Adaptive Security Virtual Appliance (ASAv), Cisco ASA for Firepower 9300 Series, Cisco ISA 3000 Industrial Security Appliance. Fixed versions: 9.1(7.7) 9.2(4.11) 9.4(4) 9.5(3) 9.6(1.5). Cisco Bug IDs: CSCuz11685.

Double free vulnerability in Cisco IOS XE 3.15S, 3.16S, and 3.17S allows remote authenticated users to cause a denial of service (device restart) via a sequence of crafted SNMP read requests, aka Bug ID CSCux13174.

Cisco IOS XE 3.15S and 3.16S on cBR-8 Converged Broadband Router devices allows remote authenticated users to cause a denial of service (NULL pointer dereference and card restart) via a crafted SNMP request, aka Bug ID CSCuu68862.

Buffer overflow in the web-based management interface on Cisco RV110W devices with firmware before 1.2.1.7, RV130W devices with firmware before 1.0.3.16, and RV215W devices with firmware before 1.3.0.8 allows remote authenticated users to cause a denial of service (device reload) via crafted configuration commands in an HTTP request, aka Bug ID CSCux82523.

A vulnerability in the IPsec code of Cisco ASA Software could allow an authenticated, remote attacker to cause a reload of the affected system. The vulnerability is due to improper parsing of malformed IPsec packets. An attacker could exploit this vulnerability by sending malformed IPsec packets to the affected system. Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability affects systems configured in routed firewall mode only and in single or multiple context mode. This vulnerability can be triggered by IPv4 and IPv6 traffic. An attacker needs to establish a valid IPsec tunnel before exploiting this vulnerability. This vulnerability affects Cisco ASA Software running on the following products: Cisco ASA 1000V Cloud Firewall, Cisco ASA 5500 Series Adaptive Security Appliances, Cisco ASA 5500-X Series Next-Generation Firewalls, Cisco ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Cisco Adaptive Security Virtual Appliance (ASAv), Cisco Firepower 9300 ASA Security Module, Cisco ISA 3000 Industrial Security Appliance. Fixed versions: 9.1(7.8) 9.2(4.15) 9.4(4) 9.5(3.2) 9.6(2). Cisco Bug IDs: CSCun16158.

Cisco IOS 15.5(3)M and 15.6(1)T0a on Cisco 1000 Connected Grid routers allows remote authenticated users to cause a denial of service (device reload) via an SNMP request for unspecified BRIDGE MIB OIDs, aka Bug ID CSCux89878.

A vulnerability in the Secure Sockets Layer (SSL) VPN feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition that prevents the creation of new SSL/Transport Layer Security (TLS) connections to an affected device. The vulnerability is due to incorrect handling of Base64-encoded strings. An attacker could exploit this vulnerability by opening many SSL VPN sessions to an affected device. The attacker would need to have valid user credentials on the affected device to exploit this vulnerability. A successful exploit could allow the attacker to overwrite a special system memory location, which will eventually result in memory allocation errors for new SSL/TLS sessions to the device, preventing successful establishment of these sessions. A reload of the device is required to recover from this condition. Established SSL/TLS connections to the device and SSL/TLS connections through the device are not affected. Note: Although this vulnerability is in the SSL VPN feature, successful exploitation of this vulnerability would affect all new SSL/TLS sessions to the device, including management sessions.

A vulnerability in the configuration of the Pluggable Authentication Module (PAM) used in Cisco Firepower Threat Defense (FTD) Software, Cisco Firepower Management Center (FMC) Software, and Cisco FXOS Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper resource management in the context of user session management. An attacker could exploit this vulnerability by connecting to an affected system and performing many simultaneous successful Secure Shell (SSH) logins. A successful exploit could allow the attacker to exhaust system resources and cause the device to reload, resulting in a DoS condition. To exploit this vulnerability, the attacker needs valid user credentials on the system.

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of Cisco FXOS Software and Cisco NX-OS Software could allow an authenticated, remote attacker to cause the SNMP application on an affected device to restart unexpectedly. The vulnerability is due to improper validation of Abstract Syntax Notation One (ASN.1)-encoded variables in SNMP packets. An attacker could exploit this vulnerability by sending a crafted SNMP packet to the SNMP daemon on the affected device. A successful exploit could allow the attacker to cause the SNMP application to restart multiple times, leading to a system-level restart and a denial of service (DoS) condition.

A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper error handling when parsing SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.  This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMP v2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMP v3, the attacker must have valid SNMP user credentials for the affected system.

A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow a remote attacker that is authenticated as a VPN user to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to incomplete error checking when parsing an HTTP header field value. An attacker could exploit this vulnerability by sending a crafted HTTP request to a targeted Remote Access SSL VPN service on an affected device. A successful exploit could allow the attacker to cause a DoS condition, which would cause the affected device to reload.

A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper error handling when parsing SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.  This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMP v2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMP v3, the attacker must have valid SNMP user credentials for the affected system.

A vulnerability in the SNMP subsystem of Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper error handling when parsing SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. For Cisco IOS and IOS XE Software, a successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. For Cisco IOS XR Software, a successful exploit could allow the attacker to cause the SNMP process to restart, resulting in an interrupted SNMP response from an affected device. Devices that are running Cisco IOS XR Software will not reload.  This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMP v2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMP v3, the attacker must have valid SNMP user credentials for the affected system.

A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper error handling when parsing SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.  This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMP v2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMP v3, the attacker must have valid SNMP user credentials for the affected system.

A vulnerability in the Internet Key Exchange version 1 (IKEv1) implementation of Cisco IOS XE Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. The attacker must have valid IKEv1 VPN credentials to exploit this vulnerability. This vulnerability is due to improper validation of IKEv1 phase 2 parameters before the IPsec security association creation request is handed off to the hardware cryptographic accelerator of an affected device. An attacker could exploit this vulnerability by sending crafted IKEv1 messages to the affected device. A successful exploit could allow the attacker to cause the device to reload.

A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper error handling when parsing SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.  This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMP v2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMP v3, the attacker must have valid SNMP user credentials for the affected system.

A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper error handling when parsing SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.  This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMP v2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMP v3, the attacker must have valid SNMP user credentials for the affected system.

A vulnerability in the TLS 1.3 implementation for a specific cipher for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software for Cisco Firepower 3100 and 4200 Series devices could allow an authenticated, remote attacker to consume resources that are associated with incoming TLS 1.3 connections, which eventually could cause the device to stop accepting any new SSL/TLS or VPN requests. This vulnerability is due to the implementation of the TLS 1.3 Cipher TLS_CHACHA20_POLY1305_SHA256. An attacker could exploit this vulnerability by sending a large number of TLS 1.3 connections with the specific TLS 1.3 Cipher TLS_CHACHA20_POLY1305_SHA256. A successful exploit could allow the attacker to cause a denial of service (DoS) condition where no new incoming encrypted connections are accepted. The device must be reloaded to clear this condition. Note: These incoming TLS 1.3 connections include both data traffic and user-management traffic. After the device is in the vulnerable state, no new encrypted connections can be accepted.

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series devices could allow an authenticated, remote attacker to cause a denial of service (DoS) condition in the Cisco AnyConnect service on an affected device. To exploit this vulnerability, the attacker must have valid VPN user credentials on the affected device. This vulnerability exists because a variable is not initialized when an SSL VPN session is established. An attacker could exploit this vulnerability by supplying crafted attributes while establishing an SSL VPN session with 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 sessions 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 without manual intervention.

A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper error handling when parsing SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.  This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMP v2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMP v3, the attacker must have valid SNMP user credentials for the affected system.

A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper error handling when parsing SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.  This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMP v2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMP v3, the attacker must have valid SNMP user credentials for the affected system.

CallManager Express (CME) on Cisco IOS before 15.0(1)XA allows remote authenticated users to cause a denial of service (device crash) by using an extension mobility (EM) phone to interact with the menu for SNR number changes, aka Bug ID CSCta63555.

Unspecified vulnerability in the SNMPv2c implementation in Cisco ACE Application Control Engine Module for Catalyst 6500 Switches and 7600 Routers before A2(1.3) and Cisco ACE 4710 Application Control Engine Appliance before A3(2.1) allows remote attackers to cause a denial of service (device reload) via a crafted SNMPv1 packet.

A vulnerability in the phone book feature of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker to cause the CPU to increase to 100% utilization, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to improper handling of the XML input. An attacker could exploit this vulnerability by sending a Session Initiation Protocol (SIP) message with a crafted XML payload to an affected device. A successful exploit could allow the attacker to exhaust CPU resources, resulting in a DoS condition. Manual intervention may be required to recover the device. This vulnerability is fixed in Cisco Expressway Series and Cisco TelePresence Video Communication Server Releases X12.5.1 and later.