An issue was discovered in Microvirt MEmu all versions prior to 7.0.2. A guest Android operating system inside the MEmu emulator contains a /system/bin/systemd binary that is run with root privileges on startup (this is unrelated to Red Hat's systemd init program, and is a closed-source proprietary tool that seems to be developed by Microvirt). This program opens TCP port 21509, presumably to receive installation-related commands from the host OS. Because everything after the installer:uninstall command is concatenated directly into a system() call, it is possible to execute arbitrary commands by supplying shell metacharacters.