Jailbreaking doesn't change anything with regards to Syncing/backup in iTunes. You can still do the same as before the jailbreak. iCloud will also work as normal.

I think what joonwei23 mean/concern is related to SSH. If you don't install SSH or install SSH and change the default password then you are safe. Problem only arises if you install SSH but did not care to change the root/mobile password. People can get into the phone using that 'hole'.

Use either terminal in iphone but I always use terminal in Mac.

Use either terminal in iphone but I always use terminal in Mac.

command:
1. ssh root@phone_ip_address i.e. ssh root@10.228.200.1
2. Enter default password = alpine
3. Once logged in, type passwd
4. It will ask you the new password
5. Once done then logout
6. Do step 1 again but change root to mobile

where did you run the command? If terminal within iphone then no need the ssh root@192.168.1.6.

That's true. If you don't install ssh, there is no need to change the password anyway.

If you install ssh, other people can access your iPhone via a network and if you didn't change your default password which everyone knows, then your iPhone will be open for everyone to access.

To be extra safe, turn off the SSH service in sbsettings if you don't use it..

Do you have sbsettings installed? if yes then find the ssh toggle in sbsettings setting page.