CVE-2020-3417: Cisco IOS XE Software Arbitrary Code Execution Vulnerability

Severity: medium (CVSS 6.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-09-24 · updated 2026-06-17
Weakness: CWE-78

Description

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: 3.18.0sp, 3.18.1asp, 3.18.1bsp, 3.18.1csp, 3.18.1gsp, 3.18.1hsp (+92)

References

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