TRENDnet TEW-827DRU devices through 2.06B04 contain a stack-based buffer overflow in the ssi binary. The overflow allows an authenticated user to execute arbitrary code by POSTing to apply.cgi via the action auto_up_fw (or auto_up_lp) with a sufficiently long update_file_name key.
github.com/kuc001/IoTFirmware/blob/master/Trendnet/TEW-827/auto_up_fw_overflow.pdf
github.com/kuc001/IoTFirmware/blob/master/Trendnet/TEW-827/auto_up_lp_overflow.pdf
github.com/kuc001/IoTFirmware/blob/master/Trendnet/TEW-827/TRENDnet-auto_up_fw.pdf
github.com/kuc001/IoTFirmware/blob/master/Trendnet/TEW-827/TRENDnet-auto_up_lp.pdf