Let's make sure first to clarify the fingerings shall we. Here are what you typically will find.

C:
E - open
B - 1st finger/1st fret
G - open
D - 2nd finger/2nd fret
A - 3rd finger/3rd fret
E - X

- Make sure first that that is what you are playing. After that, take a look at your hand and see whats happening. You want just the tips of your fingers to be playing these notes, and make sure to work your fingers to do just that. If you find that your fingers are hitting other strings and all that, it simply takes repetition to get your fingers developed to get into that position more naturally. Also, something people under-mind is the location of the thumb behind the neck. Make sure it isn't pointing upward and that it is pointed behind the neck. You can wrap the thumb around if you wish, but in the case of this chord make sure it is pointed behind the neck and allowing you to get a firm grasp on the guitar.

G:
E - 4th finger/3rd fret
B - open
G - open
D - open
A - 1st finger/2nd fret
E - 2nd finger/3rd fret

Same thing. This one tends to be a little easier as it is more spread out. Again, you simply have to work out your hands to not touch each other when you are playing each string. Pay attention to where your thumb is placed and again, use the tips of your fingers.

Good luck