CVE-2020-3234: Cisco IOS

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

A vulnerability in the virtual console authentication of Cisco IOS Software for Cisco 809 and 829 Industrial Integrated Services Routers (Industrial ISRs) and Cisco 1000 Series Connected Grid Routers (CGR1000) could allow an authenticated but low-privileged, local attacker to log in to the Virtual Device Server (VDS) of an affected device by using a set of default credentials. The vulnerability is due to the presence of weak, hard-coded credentials. An attacker could exploit this vulnerability by authenticating to the targeted device and then connecting to VDS through the device’s virtual console by using the static credentials. A successful exploit could allow the attacker to access the Linux shell of VDS as the root user.

Affected products

• Cisco IOS: version 12.2(60)ez16 only; version 15.0(2)sg11a only; version 15.3(3)jaa1 only; version 15.3(3)jpj only; version 15.4(1)cg only; version 15.4(2)cg only; …

Published 2020-06-03. Last modified 2026-06-17.