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 Cisco Discovery Protocol service of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause the service to restart, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of Cisco Discovery Protocol messages that are processed by the Cisco Discovery Protocol service. An attacker could exploit this vulnerability by sending a series of malicious Cisco Discovery Protocol messages to an affected device. A successful exploit could allow the attacker to cause the Cisco Discovery Protocol service to fail and restart. In rare conditions, repeated failures of the process could occur, which could cause the entire device to restart. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cdp-dos-G8DPLWYG This advisory is part of the February 2022 Cisco FXOS and NX-OS Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: February 2022 Cisco FXOS and NX-OS Software Security Advisory Bundled Publication.

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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-nxos-xr-udld-dos-W5hGHgtQ This advisory is part of the September 2021 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2021 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.

A vulnerability in the CLI of Cisco FXOS Software could allow an authenticated, local attacker to inject arbitrary commands that are executed with root privileges. The vulnerability is due to insufficient input validation of commands supplied by the user. An attacker could exploit this vulnerability by authenticating to a device and submitting crafted input to the affected command. A successful exploit could allow the attacker to execute commands on the underlying operating system with root privileges. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxos-cmdinj-b63rwKPm

Update from October 23, 2020: Cisco has become aware of a new Cisco Adaptive Security Appliance vulnerability that could affect the fixed releases recommended for code trains 9.13 and 9.14 in the Fixed Software section of this advisory. See the Cisco Adaptive Security Appliance Software SSL/TLS Denial of Service Vulnerability for additional information. A vulnerability in the CLI of Cisco FXOS Software could allow an authenticated, local attacker to inject arbitrary commands that are executed with root privileges. The vulnerability is due to insufficient input validation of commands supplied by the user. An attacker could exploit this vulnerability by authenticating to a device and submitting crafted input to the affected command. A successful exploit could allow the attacker to execute commands on the underlying operating system with root privileges. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxos-cmdinj-pqZvmXCr

A vulnerability in the secure boot process of Cisco FXOS Software could allow an authenticated, local attacker to bypass the secure boot mechanisms. The vulnerability is due to insufficient protections of the secure boot process. An attacker could exploit this vulnerability by injecting code into a specific file that is then referenced during the device boot process. A successful exploit could allow the attacker to break the chain of trust and inject code into the boot process of the device which would be executed at each boot and maintain persistence across reboots. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxos-sbbp-XTuPkYTn

A vulnerability in the CLI of Cisco FXOS Software could allow an authenticated, local attacker to read or write arbitrary files on the underlying operating system (OS). The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by including crafted arguments to a specific CLI command. A successful exploit could allow the attacker to read or write to arbitrary files on the underlying OS. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200226-fxos-cli-file

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). Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200226-fxos-nxos-cdp

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. 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).

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200205-fxnxos-iosxr-cdp-dos

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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191002-ftd-fpmc-dos

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause the SNMP application to leak system memory, which could cause an affected device to restart unexpectedly. The vulnerability is due to improper error handling when processing inbound SNMP packets. An attacker could exploit this vulnerability by sending multiple crafted SNMP packets to an affected device. A successful exploit could allow the attacker to cause the SNMP application to leak system memory because of an improperly handled error condition during packet processing. Over time, this memory leak could cause the SNMP application to restart multiple times, leading to a system-level restart and a denial of service (DoS) condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-nxos-snmp-dos