On certain TOTOLINK Realtek SDK based routers, an authenticated attacker may execute arbitrary OS commands via the sysCmd parameter to the boafrm/formSysCmd URI, even if the GUI (syscmd.htm) is not available. This allows for full control over the device's internals. This affects A3002RU through 2.0.0, A702R through 2.1.3, N301RT through 2.1.6, N302R through 3.4.0, N300RT through 3.4.0, N200RE through 4.0.0, N150RT through 3.4.0, and N100RE through 3.4.0.