CVE-2020-3417: Cisco IOS XE

Medium severity, CVSS 6.7. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Cisco IOS XE: version 3.18.0sp only; version 3.18.1asp only; version 3.18.1bsp only; version 3.18.1csp only; version 3.18.1gsp only; version 3.18.1hsp only; …

Published 2020-09-24. Last modified 2026-06-17.