Although this is not per se a problem related to Mozilla Firefox, you might be successful in obtaining access to blocked sites thorugh the use of any software (or Mozilla Add-on) that will allow you to access a site through a proxy or by the use of a virtual private network. However, please consider reading the University's Network Terms of Use (or similar document). It is highly likely that you are not allowed to use any form of proxy or virtual private network on the University's network. If you do, you might loose your account rendering you unable to access the network at all! So, it's up to you. There are also websites who provide a form of proxy service where you simply access the site and then enter the URL of the site you wish to access. But, as I mentioned: you might be banned from using the network if you do not comply with the rules, so please be careful and find out what you can and cannot do using the University network.