Yeah, course you have a chance. Nobody can quantify your chance, as we don't know how well you'll come across in an interview (for Cambridge), or how much wider reading/academic exploration you've done for your personal statement.
You might as well apply, but if you have Cambridge, UCL and LSE as 3 of your 5 choices, make sure the other 2 are safer options, as nobody can guarantee getting an offer from the first three, no matter how good your grades are.