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.

A vulnerability in the Secure Shell (SSH) subsystem of Cisco Small Business Managed Switches software could allow an authenticated, remote attacker to cause a reload of the affected switch, resulting in a denial of service (DoS) condition. The vulnerability is due to improper processing of SSH connections. An attacker could exploit this vulnerability by logging in to an affected switch via SSH and sending a malicious SSH message. This vulnerability affects the following Cisco products when SSH is enabled: Small Business 300 Series Managed Switches, Small Business 500 Series Stackable Managed Switches, 350 Series Managed Switches, 350X Series Stackable Managed Switches, 550X Series Stackable Managed Switches, ESW2 Series Advanced Switches. Cisco Bug IDs: CSCvb48377.

Cisco TelePresence System Software does not properly handle inactive t-shell sessions, which allows remote authenticated users to cause a denial of service (memory consumption and service outage) by establishing multiple SSH connections, aka Bug ID CSCug77610.

The generic input/output control implementation in Cisco IOS does not properly manage buffers, which allows remote authenticated users to cause a denial of service (device reload) by sending many SNMP requests at the same time, aka Bug ID CSCub41105.

The XML parser in the server in Cisco Unified Presence (CUP) allows remote authenticated users to cause a denial of service (jabberd daemon crash) via crafted XML content in an XMPP message, aka Bug ID CSCue13912.

Cisco IOS before 12.2(50)SY1 allows remote authenticated users to cause a denial of service (memory consumption) via a sequence of VTY management sessions (aka exec sessions), aka Bug ID CSCtn43662.

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.

Unspecified vulnerability in Cisco IOS before 15.3(2)T on AS5400 devices allows remote authenticated users to cause a denial of service (spurious errors) via unknown vectors, aka Bug ID CSCub61009.

Cisco IOS before 15.1(1)SY1 allows remote authenticated users to cause a denial of service (device reload) by establishing a VPN session and then sending malformed IKEv2 packets, aka Bug ID CSCub39268.

Multiple vulnerabilities in the web engine of Cisco TelePresence Collaboration Endpoint (CE) Software and Cisco RoomOS Software could allow a remote attacker to cause a denial of service (DoS) condition, view sensitive data on an affected device, or redirect users to an attacker-controlled destination. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the Simple Network Management Protocol (SNMP) implementation in Cisco ASR 920 Series Aggregation Services Router model ASR920-12SZ-IM could allow an authenticated, remote attacker to cause the device to reload. The vulnerability is due to incorrect handling of data that is returned for Cisco Discovery Protocol queries to SNMP. An attacker could exploit this vulnerability by sending a request for Cisco Discovery Protocol information by using SNMP. An exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition.

A vulnerability in the user management functionality of Cisco Enterprise NFV Infrastructure Software (NFVIS) could allow an authenticated, remote attacker to perform a denial of service (DoS) attack against an affected system. The vulnerability is due to insufficient validation of user-provided input. An attacker could exploit this vulnerability by logging in with a highly privileged user account and performing a sequence of specific user management operations that interfere with the underlying operating system. A successful exploit could allow the attacker to permanently degrade the functionality of the affected system.

A vulnerability in the web-based management interface of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to consume excessive system memory and cause a denial of service (DoS) condition on an affected system. The vulnerability is due to inefficient memory management. An attacker could exploit this vulnerability by sending a large number of crafted HTTP requests to the affected web-based management interface. A successful exploit could allow the attacker to exhaust system memory, which could cause the system to stop processing new connections and could result in a DoS condition.

A vulnerability in the Secure Shell (SSH) server code of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload. The vulnerability is due to an internal state not being represented correctly in the SSH state machine, which leads to an unexpected behavior. An attacker could exploit this vulnerability by creating an SSH connection to an affected device and using a specific traffic pattern that causes an error condition within that connection. 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 Cisco Webex Teams client for Windows could allow an authenticated, remote attacker to cause the client to crash, resulting in a denial of service (DoS) condition. The attacker needs a valid developer account to exploit this vulnerability. The vulnerability is due to insufficient input validation when processing received adaptive cards. The attacker could exploit this vulnerability by sending an adaptive card with malicious content to an existing user of the Cisco Webex Teams client for Windows. A successful exploit could allow the attacker to cause the targeted user's client to crash continuously. This vulnerability was introduced in Cisco Webex Teams client for Windows Release 3.0.13131.

A vulnerability in the Simple Network Management Protocol (SNMP) feature 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. This vulnerability is due to insufficient input validation. 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.

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. This vulnerability is due to improper control of a resource. An attacker with the ability to spoof a trusted IKEv2 site-to-site VPN peer and in possession of valid IKEv2 credentials for that peer could exploit this vulnerability by sending malformed, authenticated IKEv2 messages to an affected device. A successful exploit could allow the attacker to trigger a reload of the device.

A vulnerability in the IPSec decryption routine of Cisco IOS XE 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 buffer exhaustion that occurs while traffic on a configured IPsec tunnel is being processed. An attacker could exploit this vulnerability by sending traffic to an affected device that has a maximum transmission unit (MTU) of 1800 bytes or greater. A successful exploit could allow the attacker to cause the device to reload. To exploit this vulnerability, the attacker may need access to the trusted network where the affected device is in order to send specific packets to be processed by the device. All network devices between the attacker and the affected device must support an MTU of 1800 bytes or greater. This access requirement could limit the possibility of a successful exploit.

A vulnerability in Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&P) Software could allow an authenticated, remote attacker to cause the Cisco XCP Authentication Service on an affected device to restart, resulting in a denial of service (DoS) condition. The vulnerability is due to improper handling of login requests. An attacker could exploit this vulnerability by sending a crafted client login request to an affected device. A successful exploit could allow the attacker to cause a process to crash, resulting in a DoS condition for new login attempts. Users who are authenticated at the time of the attack would not be affected. There are workarounds that address this vulnerability.

A vulnerability in the SSL/TLS client 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. This vulnerability is due to improper memory management when a device initiates SSL/TLS connections. An attacker could exploit this vulnerability by ensuring that the device will connect to an SSL/TLS server that is using specific encryption parameters. A successful exploit could allow the attacker to cause the affected device to unexpectedly reload, resulting in a DoS condition.

A vulnerability in Cisco Smart Software Manager On-Prem (SSM On-Prem) could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incorrect handling of multiple simultaneous device registrations on Cisco SSM On-Prem. An attacker could exploit this vulnerability by sending multiple device registration requests to Cisco SSM On-Prem. A successful exploit could allow the attacker to cause a DoS condition on an affected device.

A vulnerability in the NETCONF over SSH feature of Cisco IOS XE Software could allow a low-privileged, authenticated, remote attacker to cause a denial of service condition (DoS) on an affected device. This vulnerability is due to insufficient resource management. An attacker could exploit this vulnerability by initiating a large number of NETCONF over SSH connections. A successful exploit could allow the attacker to exhaust resources, causing the device to reload and resulting in a DoS condition on an affected device.

Multiple vulnerabilities in the web engine of Cisco TelePresence Collaboration Endpoint (CE) Software and Cisco RoomOS Software could allow a remote attacker to cause a denial of service (DoS) condition, view sensitive data on an affected device, or redirect users to an attacker-controlled destination. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the web services interface of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper resource management in the HTTP server code. An attacker could exploit this vulnerability by sending a large number of HTTP requests 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 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.

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 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 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 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.

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 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 TrustSec CLI parser of Cisco IOS and Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload. This vulnerability is due to an improper interaction between the web UI and the CLI parser. An attacker could exploit this vulnerability by requesting a particular CLI command to be run through the web UI. 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 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.

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.

A vulnerability in the web-based management interface of Cisco IC3000 Industrial Compute Gateway could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability exists because the affected software improperly manages system resources. An attacker could exploit this vulnerability by opening a large number of simultaneous sessions on the web-based management interface of an affected device. A successful exploit could allow the attacker to cause a DoS condition of the web-based management interface, preventing normal management operations.

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 management REST API of Cisco Industrial Network Director (IND) could allow an authenticated, remote attacker to cause the CPU utilization to increase to 100 percent, resulting in a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of requests sent to the REST API. An attacker could exploit this vulnerability by sending a crafted request to the REST API. A successful exploit could allow the attacker to cause a permanent DoS condition that is due to high CPU utilization. Manual intervention may be required to recover the Cisco IND.

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 XML parser code of Cisco Firepower Device Manager On-Box software could allow an authenticated, remote attacker to cause an affected system to become unstable or reload. The vulnerability is due to insufficient hardening of the XML parser configuration. An attacker could exploit this vulnerability in multiple ways using a malicious file: An attacker with administrative privileges could upload a malicious XML file on the system and cause the XML code to parse the malicious file. An attacker with Clientless Secure Sockets Layer (SSL) VPN access could exploit this vulnerability by sending a crafted XML file. A successful exploit would allow the attacker to crash the XML parser process, which could cause system instability, memory exhaustion, and in some cases lead to a reload of the affected system.

Cisco NX-OS on Nexus 9000 devices 11.1(1c) allows remote authenticated users to cause a denial of service (device hang) via large files that are copied to a device's filesystem, aka Bug ID CSCuu77225.

Memory leak in Cisco IOS 12.2 in the Performance Routing Engine (PRE) module on uBR10000 devices allows remote authenticated users to cause a denial of service (memory consumption or PXF process crash) by sending docsIfMCmtsMib SNMP requests quickly, aka Bug ID CSCue65051.