I have a new version of B593_exploit.pl published. See this article about previous info.
This version has s-22 FTP hack added to it. u-12 has the classic FTP USB-share flaw where it is possible to create a FTP share of the /. Unfortunately in this box Huawei guys made the web GUI a bit smarter, you cannot do such a nice share anymore. The fortunate part is, that the guys don't check for that at the save. 
If you manage to lure the ../.. past the GUI, you can do it. That's what the exploit is about.
Example run:
./B593_exploit.pl 192.168.1.1 admin --ftp-setup \ ftpuser ftppassword
That command will share the first USB-device found at the filesystem root of the box. You have to have a physical USB-storage attached. It doesn't have to have anything on it and it won't be affected during the process. But setting a path will fail, if there is no USB-storage.
I had problems with the FTP-client, it kept complaining about FTP passive mode. I switched the client into NcFTP and that solved my problem.
When in the box the SSH passwords are at the classic /var/sshusers.cfg. If configuration is of interest to you, it can be found from /app/curcfg.xml. When the admin user's password is known, it is only a trivial task to SSH into the box and gain a shell access.
While looking around the box, I got carried away with the lteat-command. I managed to brick the box. 
But that's an another story.)