Just found vsftpd in cydia, installed and reboot, but I don't know how to create user account for server, I tried "root" with password "alpine" (the same with openssh) but no luck. Also tried to add user with adduser or useradd command, but seens there's no such command in iphone's OS...
Anyone know what can I do to log into the server? many thanks!
Step 1. Install openssh from Cydia if you haven't.
Step 2. SSH into your iphone as user:root and password:alpine (default) using putty.
Step 3. use commmand mkdir /usr/share/empty
Step 4. Use your same login credentials as above used with openssh to login to vsftpd server.