Command Injection in 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/umountUSBPartition" request. This occurs because the "formSetUSBPartitionUmount" function executes the "doSystemCmd" function with untrusted input.