In qBittorrent before 4.1.7, the function Application::runExternalProgram() located in app/application.cpp allows command injection via shell metacharacters in the torrent name parameter or current tracker parameter, as demonstrated by remote command execution via a crafted name within an RSS feed (CVE-2019-13640).
The qbittorrent package has been updated to version 4.1.9.1, fixing this issue and several others.