Cisco IOS XE Software Arbitrary Code Execution Vulnerability

A vulnerability in Cisco IOS XE Software could allow an authenticated, local attacker to execute persistent code at boot time and break the chain of trust.

This vulnerability is due to incorrect validations by boot scripts when specific ROM monitor (ROMMON) variables are set. An attacker could exploit this vulnerability by installing code to a specific directory in the underlying operating system (OS) and setting a specific ROMMON variable. A successful exploit could allow the attacker to execute persistent code on the underlying OS. To exploit this vulnerability, the attacker would need access to the root shell on the device or have physical access to the 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://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xbace-OnCEbyS [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xbace-OnCEbyS”]

This advisory is part of the September 24, 2020, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 25 Cisco Security Advisories that describe 34 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: September 2020 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication [“https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74268”].