Those are sorting URL's that google finds and goes crazy on. Block off blog.php and call it a day.
It will also do this for the calendar, usually on newer vBulletin sites for some reason if you use the site:
http://sitename.com you'll see 500 pages of calender sorting URL's.
Its fine to have the warning messages in GWT that tell you access is restricted to those URL's, they provide no value what so ever to your sites rankings, and should be blocked off as with most sorting URL's since it will just be duplicated content from else where.