TOTOLINK CP900L v4.1.5cu.798_B20221228 was discovered to contain a hardcoded password for telnet in /web_cste/cgi-bin/product.ini, which allows attackers to log in as root.
https://github.com/s4ndw1ch136/IOT-vuln-reports/blob/main/TOTOLINK%20CP900L/README.md