CVE-2020-3351: Cisco SD-WAN Firmware

High severity, CVSS 8.6. EPSS: 1.4% chance of exploitation in the next 30 days.

A vulnerability in Cisco SD-WAN Solution Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper validation of fields in Cisco SD-WAN peering messages that are encapsulated in UDP packets. An attacker could exploit this vulnerability by sending crafted UDP messages to the targeted system. A successful exploit could allow the attacker to cause services on the device to fail, resulting in a DoS condition that could impact the targeted device and other devices that depend on it.

Affected products

• Cisco SD-WAN Firmware: before 17.2.7 (fixed in 17.2.7); from 17.2.8, before 18.3.0 (fixed in 18.3.0)
• Cisco Vedge Cloud Router: affected versions not specified
• Cisco Vsmart Controller: affected versions not specified

Published 2020-07-16. Last modified 2026-06-17.