CVE-2020-3409: Cisco IOS

High severity, CVSS 7.4. EPSS: 0.5% chance of exploitation in the next 30 days.

A vulnerability in the PROFINET feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause an affected device to crash and reload, resulting in a denial of service (DoS) condition on the device. The vulnerability is due to insufficient processing logic for crafted PROFINET packets that are sent to an affected device. An attacker could exploit this vulnerability by sending crafted PROFINET packets to an affected device for processing. A successful exploit could allow the attacker to cause the device to crash and reload, resulting in a DoS condition on the device.

Affected products

• Cisco IOS: version 15.2(7)e only; version 16.11.1a only
• Cisco IOS XE: version 15.2(7)e only; version 16.11.1a only

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