A vulnerability in the Layer 2 Tunneling Protocol (L2TP) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain L2TP packets. An attacker could exploit this vulnerability by sending crafted L2TP packets to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability.

A vulnerability in Application Quality of Experience (AppQoE) and Unified Threat Defense (UTD) on Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to the mishandling of a crafted packet stream through the AppQoE or UTD application. An attacker could exploit this vulnerability by sending a crafted packet stream through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

A vulnerability in the IPv6 DHCP (DHCPv6) client module of Cisco Adaptive Security Appliance (ASA) Software, Cisco Firepower Threat Defense (FTD) Software, Cisco IOS Software, and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation of DHCPv6 messages. 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, resulting in a DoS condition. Note: To successfully exploit this vulnerability, the attacker would need to either control the DHCPv6 server or be in a man-in-the-middle position.

A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker to perform a directory traversal and access resources that are outside the filesystem mountpoint of the web UI. This vulnerability is due to an insufficient security configuration. An attacker could exploit this vulnerability by sending a crafted request to the web UI. A successful exploit could allow the attacker to gain read access to files that are outside the filesystem mountpoint of the web UI. Note: These files are located on a restricted filesystem that is maintained for the web UI. There is no ability to write to any files on this filesystem.

A vulnerability in the Cisco IOx application hosting subsystem of Cisco IOS XE Software could allow an authenticated, local attacker to elevate privileges to root on an affected device. This vulnerability is due to insufficient restrictions on the hosted application. An attacker could exploit this vulnerability by logging in to and then escaping the Cisco IOx application container. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges.

A vulnerability in the implementation of the IPv4 Virtual Fragmentation Reassembly (VFR) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper reassembly of large packets that occurs when VFR is enabled on either a tunnel interface or on a physical interface that is configured with a maximum transmission unit (MTU) greater than 4,615 bytes. An attacker could exploit this vulnerability by sending fragmented packets through a VFR-enabled interface on an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

A vulnerability in the processing of malformed Common Industrial Protocol (CIP) packets that are sent to Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient input validation during processing of CIP packets. An attacker could exploit this vulnerability by sending a malformed CIP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to unexpectedly reload, resulting in a DoS condition.

A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote attacker to perform an injection attack against an affected device. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending crafted input to the web UI API. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges. To exploit this vulnerability, an attacker must have valid Administrator privileges on the affected device.

A vulnerability in the CLI of stand-alone Cisco IOS XE SD-WAN Software and Cisco SD-WAN Software could allow an authenticated, local attacker to delete arbitrary files from the file system of an affected device. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by injecting arbitrary file path information when using commands in the CLI of an affected device. A successful exploit could allow the attacker to delete arbitrary files from the file system of the affected device.

A vulnerability in the UDP processing functionality of Cisco IOS XE Software for Embedded Wireless Controllers on Catalyst 9100 Series Access Points could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to the improper processing of UDP datagrams. An attacker could exploit this vulnerability by sending malicious UDP datagrams to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Multiple vulnerabilities in the CLI of Cisco SD-WAN Software could allow an authenticated, local attacker to gain elevated privileges. These vulnerabilities are due to improper access controls on commands within the application CLI. An attacker could exploit these vulnerabilities by running a malicious command on the application CLI. A successful exploit could allow the attacker to execute arbitrary commands as the root user.

Multiple vulnerabilities in the CLI of Cisco SD-WAN Software could allow an authenticated, local attacker to gain elevated privileges. These vulnerabilities are due to improper access controls on commands within the application CLI. An attacker could exploit these vulnerabilities by running a malicious command on the application CLI. A successful exploit could allow the attacker to execute arbitrary commands as the root user.

A vulnerability in the AppNav-XE feature 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 the incorrect handling of certain TCP segments. An attacker could exploit this vulnerability by sending a stream of crafted TCP traffic at a high rate through an interface of an affected device. That interface would need to have AppNav interception enabled. A successful exploit could allow the attacker to cause the 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 a specific CLI command that is run on Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to overwrite arbitrary files in the configuration database of an affected device. This vulnerability is due to insufficient validation of specific CLI command parameters. An attacker could exploit this vulnerability by issuing that command with specific parameters. A successful exploit could allow the attacker to overwrite the content of the configuration database and gain root-level access to an affected device.

A vulnerability in the ISDN subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient input validation when the ISDN Q.931 messages are processed. An attacker could exploit this vulnerability by sending a malicious ISDN Q.931 message to an affected device. A successful exploit could allow the attacker to cause the process to crash, resulting in a reload of the affected device.

A vulnerability in the IP Address Resolution Protocol (ARP) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation Services Routers with a 20-Gbps Embedded Services Processor (ESP) installed could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service condition. The vulnerability is due to insufficient error handling when an affected device has reached platform limitations. An attacker could exploit this vulnerability by sending a malicious series of IP ARP messages to an affected device. A successful exploit could allow the attacker to exhaust system resources, which would eventually cause the affected device to reload.

A vulnerability in the file system permissions of Cisco IOS XE Software could allow an authenticated, local attacker to obtain read and write access to critical configuration or system files. The vulnerability is due to insufficient file system permissions on an affected device. An attacker could exploit this vulnerability by connecting to an affected device's guest shell, and accessing or modifying restricted files. A successful exploit could allow the attacker to view or modify restricted information or configurations that are normally not accessible to system administrators.

A vulnerability in the Split DNS feature of Cisco IOS Software and 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. The vulnerability occurs because the regular expression (regex) engine that is used with the Split DNS feature of affected releases may time out when it processes the DNS name list configuration. An attacker could exploit this vulnerability by trying to resolve an address or hostname that the affected device handles. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

A vulnerability in the RESTCONF and NETCONF-YANG access control list (ACL) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload. The vulnerability is due to incorrect processing of the ACL that is tied to the RESTCONF or NETCONF-YANG feature. An attacker could exploit this vulnerability by accessing the device using RESTCONF or NETCONF-YANG. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition.