An issue was discovered on D-Link DCS-1100 and DCS-1130 devices. The binary rtspd in /sbin folder of the device handles all the rtsp connections received by the device. It seems that the binary performs a memcpy operation at address 0x00011E34 with the value sent in the "Authorization: Basic" RTSP header and stores it on the stack. The number of bytes to be copied are calculated based on the length of the string sent in the RTSP header by the client. As a result, memcpy copies more data then it can hold on stack and this results in corrupting the registers for the caller function sub_F6CC which results in memory corruption. The severity of this attack is enlarged by the fact that the same value is then copied on the stack in the function 0x00011378 and this allows to overflow the buffer allocated and thus control the PC register which will result in arbitrary code execution on the device.
