Different Domains

Hi
I need your help…
I am starting to work on a WordPress site that has in ‘the WordPress Address (URL’) and ‘Site Address (URL’) two different domains.
For example:

WordPress Address (URL): http://example-abc.com
Site Address (URL): http://www.example-123.com

The site is mixed with two domains:
In Medias the ‘File URL:’ (http://example-abc.com/wp-content/uploads/2013/12/DSC_02911.jpg) and the ‘Permalink:’ (http://www.example-123.com/bla/dsc_0291-2/) of the images are different and much more.
The site is running….but:
Is this WordPress advanced standard or is here a big mistake?