Are these the wrong tires for my Chevy Malibu, 55's on the front and 65's on the...

[Heart Felt]

...rear? I just bought a used Chevy Malibu from a Chevy dealership. The tires on the front are 205/55/R15 and on the rear the tires are 205/65/R15. Should all four tires have matched specifications? Is it bad to have 55's on the front and 65's on the rear? I am considering having the dealer correct the problem if it is a problem that they sold the car this way.
Thank you for your reply.
It is a 2004 Chevy Malibu - std with 4 cyl.