CVE-2021-27710: Totolink a720r Firmware

Critical severity, CVSS 9.8. EPSS: 7.9% chance of exploitation in the next 30 days.

Command Injection in TOTOLINK X5000R router with firmware v9.1.0u.6118_B20201102, and TOTOLINK A720R router with firmware v4.1.5cu.470_B20200911 allows remote attackers to execute arbitrary OS commands by sending a modified HTTP request. This occurs because the function executes glibc's system function with untrusted input. In the function, "ip" parameter is directly passed to the attacker, allowing them to control the "ip" field to attack the OS.

Affected products

• Totolink a720r Firmware: version 4.1.5cu.470_b20200911 only
• Totolink x5000r Firmware: version 9.1.0u.6118_b20201102 only

Published 2021-04-14. Last modified 2026-06-17.