An issue was discovered on Xiaomi Mi WiFi R3G devices before 2.28.23-stable. The backup file is in tar.gz format. After uploading the application uses the tar zxf command to decompress so one can control the contents of the files in the decompressed directory. In addition the application's sh script for testing upload and download speeds reads a URL list from /tmp/speedtest_urls.xml and there is a command injection vulnerability as demonstrated by api/xqnetdetect/netspeed.