A vulnerability in TACACS+ and RADIUS remote authentication for Cisco NX-OS Software could allow an unauthenticated, local attacker to cause an affected device to unexpectedly reload. This vulnerability is due to incorrect input validation when processing an authentication attempt if the directed request option is enabled for TACACS+ or RADIUS. An attacker could exploit this vulnerability by entering a crafted string at the login prompt of an affected device. A successful exploit could allow the attacker to cause the affected device to unexpectedly reload, resulting in a denial of service (DoS) condition.

A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of arguments that are passed to specific CLI commands. An attacker could exploit this vulnerability by including crafted input as the argument of an affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with the privileges of the currently logged-in user.

A vulnerability in the Cisco Discovery Protocol feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code with root privileges or cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper input validation of specific values that are within a Cisco Discovery Protocol message. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to execute arbitrary code with root privileges or cause the Cisco Discovery Protocol process to crash and restart multiple times, which would cause the affected device to reload, resulting in a DoS condition. Note: Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

A vulnerability in the OSPF version 3 (OSPFv3) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incomplete input validation of specific OSPFv3 packets. An attacker could exploit this vulnerability by sending a malicious OSPFv3 link-state advertisement (LSA) to an affected device. A successful exploit could allow the attacker to cause the OSPFv3 process to crash and restart multiple times, causing the affected device to reload and resulting in a DoS condition. Note: The OSPFv3 feature is disabled by default. To exploit this vulnerability, an attacker must be able to establish a full OSPFv3 neighbor state with an affected device. For more information about exploitation conditions, see the Details section of this advisory.

A vulnerability in the Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software, Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload. This vulnerability is due to improper input validation of the UDLD packets. An attacker could exploit this vulnerability by sending specifically crafted UDLD packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The UDLD feature is disabled by default, and the conditions to exploit this vulnerability are strict. An attacker must have full control of a directly connected device. On Cisco IOS XR devices, the impact is limited to the reload of the UDLD process.

A vulnerability in the implementation of the system login block-for command for Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a login process to unexpectedly restart, causing a denial of service (DoS) condition. This vulnerability is due to a logic error in the implementation of the system login block-for command when an attack is detected and acted upon. An attacker could exploit this vulnerability by performing a brute-force login attack on an affected device. A successful exploit could allow the attacker to cause a login process to reload, which could result in a delay during authentication to the affected device.

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 an affected device. This vulnerability exists because the software improperly releases resources when it processes certain IPv6 packets that are destined to an affected device. An attacker could exploit this vulnerability by sending multiple crafted IPv6 packets to an affected device. A successful exploit could cause the network stack to run out of available buffers, impairing operations of control plane and management plane protocols and resulting in a DoS condition. Manual intervention would be required to restore normal operations on the affected device. For more information about the impact of this vulnerability, see the Details section of this advisory.

A vulnerability in the Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code with administrative privileges or 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 crafted Cisco UDLD protocol packets to a directly connected, affected device. A successful exploit could allow the attacker to execute arbitrary code with administrative privileges or cause the Cisco UDLD process to crash and restart multiple times, causing the affected device to reload and resulting in a DoS condition. Note: The UDLD feature is disabled by default, and the conditions to exploit this vulnerability are strict. The attacker needs full control of a directly connected device. That device must be connected over a port channel that has UDLD enabled. To trigger arbitrary code execution, both the UDLD-enabled port channel and specific system conditions must exist. In the absence of either the UDLD-enabled port channel or the system conditions, attempts to exploit this vulnerability will result in a DoS condition. It is possible, but highly unlikely, that an attacker could control the necessary conditions for exploitation. The CVSS score reflects this possibility. However, given the complexity of exploitation, Cisco has assigned a Medium Security Impact Rating (SIR) to this vulnerability.

A vulnerability in ICMP Version 6 (ICMPv6) processing in Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a slow system memory leak, which over time could lead to a denial of service (DoS) condition. This vulnerability is due to improper error handling when an IPv6-configured interface receives a specific type of ICMPv6 packet. An attacker could exploit this vulnerability by sending a sustained rate of crafted ICMPv6 packets to a local IPv6 address on a targeted device. A successful exploit could allow the attacker to cause a system memory leak in the ICMPv6 process on the device. As a result, the ICMPv6 process could run out of system memory and stop processing traffic. The device could then drop all ICMPv6 packets, causing traffic instability on the device. Restoring device functionality would require a device reboot.

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected system. This vulnerability is due to insufficient CSRF protections for the NX-API on an affected device. An attacker could exploit this vulnerability by persuading a user of the NX-API to follow a malicious link. A successful exploit could allow the attacker to perform arbitrary actions with the privilege level of the affected user. The attacker could view and modify the device configuration. Note: The NX-API feature is disabled by default.

A vulnerability in the Cisco Fabric Services component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated attacker to cause process crashes, which could result in a denial of service (DoS) condition on an affected device. The attack vector is configuration dependent and could be remote or adjacent. For more information about the attack vector, see the Details section of this advisory. The vulnerability is due to insufficient error handling when the affected software parses Cisco Fabric Services messages. An attacker could exploit this vulnerability by sending malicious Cisco Fabric Services messages to an affected device. A successful exploit could allow the attacker to cause a reload of an affected device, which could result in a DoS condition.

A vulnerability in the local management (local-mgmt) CLI of Cisco UCS Manager Software could allow an authenticated, local attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper handling of CLI command parameters. An attacker could exploit this vulnerability by executing specific commands on the local-mgmt CLI on an affected device. A successful exploit could allow the attacker to cause internal system processes to fail to terminate properly, which could result in a buildup of stuck processes and lead to slowness in accessing the UCS Manager CLI and web UI. A sustained attack may result in a restart of internal UCS Manager processes and a temporary loss of access to the UCS Manager CLI and web UI.

A vulnerability in the Call Home feature of Cisco NX-OS Software could allow an authenticated, remote attacker to inject arbitrary commands that could be executed with root privileges on the underlying operating system (OS). The vulnerability is due to insufficient input validation of specific Call Home configuration parameters when the software is configured for transport method HTTP. An attacker could exploit this vulnerability by modifying parameters within the Call Home configuration on an affected device. A successful exploit could allow the attacker to execute arbitrary commands with root privileges on the underlying OS.

Multiple products that implement the IP Encapsulation within IP standard (RFC 2003, STD 1) decapsulate and route IP-in-IP traffic without any validation, which could allow an unauthenticated remote attacker to route arbitrary traffic via an exposed network interface and lead to spoofing, access control bypass, and other unexpected network behaviors.

A vulnerability in the Cisco Discovery Protocol feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code as root or cause a denial of service (DoS) condition on an affected device. The vulnerability exists because of insufficiently validated Cisco Discovery Protocol packet headers. An attacker could exploit this vulnerability by sending a crafted Cisco Discovery Protocol packet to a Layer 2-adjacent affected device. A successful exploit could allow the attacker to cause a buffer overflow that could allow the attacker to execute arbitrary code as root or cause a DoS condition on the affected device. Note: Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent). Note: This vulnerability is different from the following Cisco FXOS and NX-OS Software Cisco Discovery Protocol vulnerabilities that Cisco announced on Feb. 5, 2020: Cisco FXOS, IOS XR, and NX-OS Software Cisco Discovery Protocol Denial of Service Vulnerability and Cisco NX-OS Software Cisco Discovery Protocol Remote Code Execution Vulnerability.

A vulnerability in Cisco IOS XE SD-WAN Software could allow an unauthenticated, local attacker to gain unauthorized access to an affected device. The vulnerability is due to the existence of default credentials within the default configuration of an affected device. An attacker who has access to an affected device could log in with elevated privileges. A successful exploit could allow the attacker to take complete control of the device. This vulnerability affects Cisco devices that are running Cisco IOS XE SD-WAN Software releases 16.11 and earlier.

A vulnerability in the Cisco Discovery Protocol implementation for Cisco FXOS Software, Cisco IOS XR Software, and Cisco NX-OS 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 a missing check when the affected software processes Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to exhaust system memory, causing the device to reload. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

A vulnerability in the Cisco Discovery Protocol implementation for Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability exists because the Cisco Discovery Protocol parser does not properly validate input for certain fields in a Cisco Discovery Protocol message. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. An successful exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges on an affected device. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

A vulnerability in the implementation of a CLI diagnostic command in Cisco FXOS Software and Cisco NX-OS Software could allow an authenticated, local attacker to view sensitive system files that should be restricted. The attacker could use this information to conduct additional reconnaissance attacks. The vulnerability is due to incomplete role-based access control (RBAC) verification. An attacker could exploit this vulnerability by authenticating to the device and issuing a specific CLI diagnostic command with crafted user-input parameters. An exploit could allow the attacker to perform an arbitrary read of a file on the device, and the file may contain sensitive information. The attacker needs valid device credentials to exploit this vulnerability.

A vulnerability in a CLI command related to the virtualization manager (VMAN) in Cisco NX-OS Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying Linux operating system with root privileges. The vulnerability is due to insufficient validation of arguments passed to a specific VMAN CLI command on an affected device. An attacker could exploit this vulnerability by including malicious input as the argument of an affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying Linux operating system with root privileges, which may lead to complete system compromise. An attacker would need valid administrator credentials to exploit this vulnerability.