A vulnerability in the IPv6 DHCP version 6 (DHCPv6) relay and server features of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to insufficient validation of data boundaries. An attacker could exploit this vulnerability by sending crafted DHCPv6 messages to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly.

A vulnerability in the SSH implementation of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload. This vulnerability is due to improper handling of resources during an exceptional situation. An attacker could exploit this vulnerability by continuously connecting to an affected device and sending specific SSH requests. A successful exploit could allow the attacker to cause the affected device to reload.

Multiple vulnerabilities in the Cisco IOx application hosting environment on multiple Cisco platforms could allow an attacker to inject arbitrary commands into the underlying host operating system, execute arbitrary code on the underlying host operating system, install applications without being authenticated, or conduct a cross-site scripting (XSS) attack against a user of the affected software. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the Voice Telephony Service Provider (VTSP) service of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass configured destination patterns and dial arbitrary numbers. This vulnerability is due to insufficient validation of dial strings at Foreign Exchange Office (FXO) interfaces. An attacker could exploit this vulnerability by sending a malformed dial string to an affected device via either the ISDN protocol or SIP. A successful exploit could allow the attacker to conduct toll fraud, resulting in unexpected financial impact to affected customers.

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 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 Internet Key Exchange Version 2 (IKEv2) support for the AutoReconnect feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to exhaust the free IP addresses from the assigned local pool. This vulnerability occurs because the code does not release the allocated IP address under certain failure conditions. An attacker could exploit this vulnerability by trying to connect to the device with a non-AnyConnect client. A successful exploit could allow the attacker to exhaust the IP addresses from the assigned local pool, which prevents users from logging in and leads to a denial of service (DoS) condition.

A vulnerability in the web UI of Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected system. The vulnerability is due to insufficient CSRF protections for the web UI on an affected device. An attacker could exploit this vulnerability by persuading a user of the interface to follow a malicious link. A successful exploit could allow the attacker to perform arbitrary actions with the privilege level of the targeted user. If the user has administrative privileges, the attacker could alter the configuration, execute commands, or reload an affected device.

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

A vulnerability in the Topology Discovery Service of Cisco One Platform Kit (onePK) in Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient length restrictions when the onePK Topology Discovery Service parses Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol message to an affected device. An exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges, or to cause a process crash, which could result in a reload of the device and cause a DoS condition.

A vulnerability in the Tool Command Language (Tcl) interpreter of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, local attacker with privileged EXEC credentials to execute arbitrary code on the underlying operating system (OS) with root privileges. The vulnerability is due to insufficient input validation of data passed to the Tcl interpreter. An attacker could exploit this vulnerability by loading malicious Tcl code on an affected device. A successful exploit could allow the attacker to cause memory corruption or execute the code with root privileges on the underlying OS of the affected device.

A vulnerability in the Tool Command Language (Tcl) interpreter of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, local attacker with privileged EXEC credentials to cause a denial of service (DoS) condition on an affected system. The vulnerability is due to insufficient input validation of data passed to the Tcl interpreter. An attacker could exploit this vulnerability by executing crafted Tcl arguments on an affected device. An exploit could allow the attacker to cause the affected device to reload, resulting 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 FTP application layer gateway (ALG) functionality used by Network Address Translation (NAT), NAT IPv6 to IPv4 (NAT64), and the Zone-Based Policy Firewall (ZBFW) in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to a buffer overflow that occurs when an affected device inspects certain FTP traffic. An attacker could exploit this vulnerability by performing a specific FTP transfer through the device. A successful exploit could allow the attacker to cause the device to reload.

A vulnerability in the Hot Standby Router Protocol (HSRP) subsystem of Cisco IOS and IOS XE Software could allow an unauthenticated, adjacent attacker to receive potentially sensitive information from an affected device. The vulnerability is due to insufficient memory initialization. An attacker could exploit this vulnerability by receiving HSRPv2 traffic from an adjacent HSRP member. A successful exploit could allow the attacker to receive potentially sensitive information from the adjacent device.

A vulnerability in the Cisco Smart Call Home feature of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to gain unauthorized read access to sensitive data using an invalid certificate. The vulnerability is due to insufficient certificate validation by the affected software. An attacker could exploit this vulnerability by supplying a crafted certificate to an affected device. A successful exploit could allow the attacker to conduct man-in-the-middle attacks to decrypt confidential information on user connections to the affected software.

A vulnerability in the Cisco Network Plug-and-Play (PnP) agent of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to gain unauthorized access to sensitive data. The vulnerability exists because the affected software insufficiently validates certificates. An attacker could exploit this vulnerability by supplying a crafted certificate to an affected device. A successful exploit could allow the attacker to conduct man-in-the-middle attacks to decrypt and modify confidential information on user connections to the affected software.

A vulnerability in the Network-Based Application Recognition (NBAR) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. This vulnerability are due to a parsing issue on DNS packets. An attacker could exploit this vulnerability by sending crafted DNS packets through routers that are running an affected version and have NBAR enabled. 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 the Network-Based Application Recognition (NBAR) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. This vulnerability is due to a parsing issue on DNS packets. An attacker could exploit this vulnerability by sending crafted DNS packets through routers that are running an affected version and have NBAR enabled. 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 the Network-Based Application Recognition (NBAR) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. This vulnerability is due to a parsing issue on DNS packets. An attacker could exploit these vulnerabilities by sending crafted DNS packets through routers that are running an affected version and have NBAR enabled. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition.