CVE-2021-27691: Tendacn g0 Firmware

Critical severity, CVSS 9.8. EPSS: 25.2% chance of exploitation in the next 30 days.

Command Injection in Tenda G0 routers with firmware versions v15.11.0.6(9039)_CN and v15.11.0.5(5876)_CN , and Tenda G1 and G3 routers with firmware versions v15.11.0.17(9502)_CN or v15.11.0.16(9024)_CN allows remote attackers to execute arbitrary OS commands via a crafted action/setDebugCfg request. This occurs because the "formSetDebugCfg" function executes glibc's system function with untrusted input.

Affected products

• Tendacn g0 Firmware: version 15.11.0.5(5876)_cn only; version 15.11.0.6(9039)_cn only
• Tendacn g1 Firmware: version 15.11.0.16(9024)_cn only; version 15.11.0.17(9502)_cn only
• Tendacn g3 Firmware: version 15.11.0.16(9024)_cn only; version 15.11.0.17(9502)_cn only

Published 2021-04-16. Last modified 2026-06-17.