CVE-2020-5759: Grandstream UCM6202 Firmware

Critical severity, CVSS 9.8. EPSS: 3.2% chance of exploitation in the next 30 days.

Grandstream UCM6200 series firmware version 1.0.20.23 and below is vulnerable to OS command injection via SSH. An authenticated remote attacker can execute commands as the root user by issuing a specially crafted "unset" command.

Affected products

• Grandstream UCM6202 Firmware: up to and including 1.0.20.23
• Grandstream UCM6204 Firmware: up to and including 1.0.20.23
• Grandstream UCM6208 Firmware: up to and including 1.0.20.23

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