CVE-2020-3426: Cisco IOS

Critical severity, CVSS 9.1. EPSS: 2.2% chance of exploitation in the next 30 days.

A vulnerability in the implementation of the Low Power, Wide Area (LPWA) subsystem of Cisco IOS Software for Cisco 800 Series Industrial Integrated Services Routers (Industrial ISRs) and Cisco 1000 Series Connected Grid Routers (CGR1000) could allow an unauthenticated, remote attacker to gain unauthorized read access to sensitive data or cause a denial of service (DoS) condition. The vulnerability is due to a lack of input and validation checking mechanisms for virtual-LPWA (VLPWA) protocol modem messages. An attacker could exploit this vulnerability by supplying crafted packets to an affected device. A successful exploit could allow the attacker to gain unauthorized read access to sensitive data or cause the VLPWA interface of the affected device to shut down, resulting in DoS condition.

Affected products

• Cisco IOS: affected versions not specified

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