A vulnerability in the boot logic of Cisco IOS XE Software could allow an authenticated, local attacker with level 15 privileges or an unauthenticated attacker with physical access to execute arbitrary code on the underlying Linux operating system of an affected device.
This vulnerability is due to incorrect validations of specific function arguments that are passed to the boot script. An attacker could exploit this vulnerability by tampering with a specific file, which an affected device would process during the initial boot process. On systems that are protected by the Unified Extensible Firmware Interface (UEFI) secure boot feature, a successful exploit could allow the attacker to execute unsigned code at boot time and bypass the image verification check in the secure boot process of the affected device.
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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-XE-ACE-75K3bRWe ["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-XE-ACE-75K3bRWe"]
This advisory is part of the March 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: March 2021 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://tools.cisco.com/security/center/viewErp.x?alertId=ERP-74408"].