Upload feature is broken. When uploading a simple file, the application return Your image was not uploaded.
The apache log give this error.
docker exec [dvwa] cat /var/log/apache2/error.log
[Thu Dec 01 03:20:54.955287 2016] [:error] [pid 545] [client 172.17.0.1:46222] PHP Warning: move_uploaded_file(): Unable to move '/tmp/php7hTEUz' to '../../hackable/uploads/test.gif' in /app/vulnerabilities/upload/source/low.php on line 7, referer: http://localhost:8001/vulnerabilities/upload/
> docker exec [dvwa] ls -la /app/hackable/uploads
total 12
drwxrwxr-x 2 root root 4096 May 1 2013 .
drwxrwxr-x 4 root root 4096 May 1 2013 ..
-rw-rw-r-- 1 root root 667 May 1 2013 dvwa_email.png